refactor from c to racket

30 files changed, 214 insertions, 1131 deletions

diff --git a/advent-of-code/2023/.gitignore b/advent-of-code/2023/.gitignore
deleted file mode 100644
index 5e92c04..0000000
--- a/advent-of-code/2023/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-part1
-part2
diff --git a/advent-of-code/2023/01/1.rkt b/advent-of-code/2023/01/1.rkt
index 58475ed..865e72e 100644
--- a/advent-of-code/2023/01/1.rkt
+++ b/advent-of-code/2023/01/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 
diff --git a/advent-of-code/2023/01/2.rkt b/advent-of-code/2023/01/2.rkt
index 85a0fd6..d00e2f9 100644
--- a/advent-of-code/2023/01/2.rkt
+++ b/advent-of-code/2023/01/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 
diff --git a/advent-of-code/2023/02/1.rkt b/advent-of-code/2023/02/1.rkt
index ab1e4c2..9213079 100644
--- a/advent-of-code/2023/02/1.rkt
+++ b/advent-of-code/2023/02/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 
diff --git a/advent-of-code/2023/02/2.rkt b/advent-of-code/2023/02/2.rkt
index da45d56..88fa571 100644
--- a/advent-of-code/2023/02/2.rkt
+++ b/advent-of-code/2023/02/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 
diff --git a/advent-of-code/2023/03/1.rkt b/advent-of-code/2023/03/1.rkt
new file mode 100644
index 0000000..537d65f
--- /dev/null
+++ b/advent-of-code/2023/03/1.rkt
@@ -0,0 +1,84 @@
+#lang racket/base
+
+(require "../lib/utils.rkt")
+(require "../lib/obj.rkt")
+
+(define (read-input)
+  (call-with-input-file "input"
+    (lambda (fp) 
+      (list->vector (get-lines fp)))))
+
+(define schema (read-input))
+
+(define (char-at line col)
+  (string-ref (vector-ref schema line) col))
+
+(define height (vector-length schema))
+(define width (string-length (vector-ref schema 0)))
+
+(define make-num (obj-maker 'line 'col 'value 'length))
+
+(define (scan-nums)
+  (define nums '())
+  (let loop ((i 0))
+    (if (>= i height)
+      (void)
+      (let ()
+        (let loop ((j 0))
+            (define curline (vector-ref schema i))
+            (if (>= j width)
+            (void)
+            (let ()
+                (define next 1)
+                (define (find-next)
+                  (if (or (>= (+ j next) 140)
+                          (not (char-numeric? (char-at i (+ j next)))))
+                    (void)
+                    (let ()
+                      (set! next (+ 1 next))
+                      (find-next))))
+                (if (char-numeric? (char-at i j))
+                  (let ()
+                    (find-next)
+                    (define value (string->number (substring curline j (+ j next))))
+                    (set! nums (cons (make-num i j value next) nums)))
+                  (void))
+                (loop (+ j next)))))
+        (loop (+ 1 i)))))
+  (reverse nums))
+(define nums (scan-nums))
+
+(define (is-symbol? c)
+  (and (not (char-numeric? c))
+       (not (char=? #\. c))))
+
+(define (collect-adjacent num)
+  (define left
+    (if (= 0 (num 'col))
+      '()
+      (list (char-at (num 'line) (- (num 'col) 1)))))
+  (define right
+    (if (= width (+ (num 'col) (num 'length)))
+      '()
+      (list (char-at (num 'line) (+ (num 'col) (num 'length))))))
+  (define up
+    (if (= 0 (num 'line))
+      '()
+      (string->list
+        (substring (vector-ref schema (- (num 'line) 1))
+                   (max 0 (- (num 'col) 1))
+                   (min width (+ (num 'col) (num 'length) 1))))))
+  (define down
+    (if (= (- height 1) (num 'line))
+      '()
+      (string->list
+        (substring (vector-ref schema (+ (num 'line) 1))
+                   (max 0 (- (num 'col) 1))
+                   (min width (+ (num 'col) (num 'length) 1))))))
+  (append left right up down))
+
+(define (is-part-num? num)
+  (findf is-symbol? (collect-adjacent num)))
+
+(apply + (map (lambda (x) (x 'value))
+              (filter is-part-num? nums)))
\ No newline at end of file
diff --git a/advent-of-code/2023/03/2.rkt b/advent-of-code/2023/03/2.rkt
new file mode 100644
index 0000000..721a9d1
--- /dev/null
+++ b/advent-of-code/2023/03/2.rkt
@@ -0,0 +1,106 @@
+#lang racket
+
+(require "../lib/utils.rkt")
+(require "../lib/obj.rkt")
+
+(define (read-input)
+  (call-with-input-file "input"
+    (lambda (fp) 
+      (list->vector (get-lines fp)))))
+
+(define schema (read-input))
+
+(define (char-at line col)
+  (string-ref (vector-ref schema line) col))
+
+(define height (vector-length schema))
+(define width (string-length (vector-ref schema 0)))
+
+(define make-num (obj-maker 'line 'col 'value 'length))
+
+(define (scan-nums)
+  (define nums '())
+  (let loop ((i 0))
+    (if (>= i height)
+      (void)
+      (let ()
+        (let loop ((j 0))
+            (define curline (vector-ref schema i))
+            (if (>= j width)
+            (void)
+            (let ()
+                (define next 1)
+                (define (find-next)
+                  (if (or (>= (+ j next) 140)
+                          (not (char-numeric? (char-at i (+ j next)))))
+                    (void)
+                    (let ()
+                      (set! next (+ 1 next))
+                      (find-next))))
+                (if (char-numeric? (char-at i j))
+                  (let ()
+                    (find-next)
+                    (define value (string->number (substring curline j (+ j next))))
+                    (set! nums (cons (make-num i j value next) nums)))
+                  (void))
+                (loop (+ j next)))))
+        (loop (+ 1 i)))))
+  (reverse nums))
+(define nums (scan-nums))
+
+(define (is-symbol? c)
+  (and (not (char-numeric? c))
+       (not (char=? #\. c))))
+
+(define (collect-adjacent-positions num)
+  (define (position-range line start end)
+    (define delta (- end start))
+    (map list (repeat delta line) (range start end)))
+  (define left
+    (if (= 0 (num 'col))
+      '()
+      (list (list (num 'line) (- (num 'col) 1)))))
+  (define right
+    (if (= width (+ (num 'col) (num 'length)))
+      '()
+      (list (list (num 'line) (+ (num 'col) (num 'length))))))
+  (define up
+    (if (= 0 (num 'line))
+      '()
+      (position-range (- (num 'line) 1)
+                      (max 0 (- (num 'col) 1))
+                      (min width (+ (num 'col) (num 'length) 1)))))
+  (define down
+    (if (= (- height 1) (num 'line))
+      '()
+      (position-range (+ (num 'line) 1)
+                      (max 0 (- (num 'col) 1))
+                      (min width (+ (num 'col) (num 'length) 1)))))
+  (append left right up down))
+
+(define asterisks (make-hash))
+
+(define (mark-adj-asterisk num)
+  (define adjs (collect-adjacent-positions num))
+  (define (mark coord)
+    (if (not (char=? #\* (char-at (car coord) (cadr coord))))
+      (void)
+      (let ()
+        (when (not (hash-has-key? asterisks coord))
+          (hash-set! asterisks coord '()))
+        (hash-set! asterisks coord (cons (num 'value) (hash-ref asterisks coord))))))
+  (for-each mark adjs))
+
+(for-each mark-adj-asterisk nums)
+
+(define aster-list (hash->list asterisks))
+
+(define (is-gear? aster)
+  (define nums-list (cdr aster))
+  (= 2 (length nums-list)))
+
+(define (power aster)
+  (define nums-list (cdr aster))
+  (* (car nums-list) (cadr nums-list)))
+
+(apply + (map power (filter is-gear? aster-list)))
diff --git a/advent-of-code/2023/03/Makefile b/advent-of-code/2023/03/Makefile
deleted file mode 100644
index 44480b6..0000000
--- a/advent-of-code/2023/03/Makefile
+++ /dev/null
@@ -1,14 +0,0 @@
-all: run
-
-run: part1 part2
-	./part1
-	./part2
-
-part1: part1.c
-	gcc -g -I../lib/ ../lib/*.c part1.c -o part1
-
-part2: part2.c
-	gcc -g -I../lib/ ../lib/*.c part2.c -o part2
-
-clean:
-	rm part1 part2
diff --git a/advent-of-code/2023/03/part1.c b/advent-of-code/2023/03/part1.c
deleted file mode 100644
index 4ae9ef9..0000000
--- a/advent-of-code/2023/03/part1.c
+++ /dev/null
@@ -1,130 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#include <assert.h>
-
-#include "vec.h"
-#include "str.h"
-
-void* read_input() {
-    FILE* fp = fopen("./input", "r");
-    void *vec = new_vec();
-    while(1) {
-        char *line = fgetline(fp);
-        if (line == NULL) break;
-        char *stripped = str_strip(line);
-        if (strlen(stripped) == 0) break;
-        vec_push_back(vec, stripped);
-    }
-    return vec;
-}
-
-typedef struct {
-    int line;
-    int column;
-    int value;
-    int length;
-} num_t;
-
-void *parse_nums(void *schema) {
-    void *nums = new_vec();
-    int j = 0;
-    const int IN_NUM = 0, IDLE = 1;
-    int state = IDLE;
-    for (int i = 0; i < vec_size(schema); i++) {
-        char *line = vec_get(schema, i);
-        int line_len = strlen(line);
-        int value = 0;
-        int length = 0;
-        state = IDLE;
-        j = 0;
-        while (1) {
-            char c = '.';
-            if (j < line_len) c = line[j];
-            if (state == IDLE) {
-                if (isdigit(c)) {
-                    state = IN_NUM;
-                    continue;
-                } else {
-                    j++;
-                    if (j >= line_len) break;
-                    continue;
-                }
-            } else if (state == IN_NUM) {
-                if (isdigit(c)) {
-                    value = value * 10 + (c - '0'); 
-                    length++;
-                    j++;
-                    continue;
-                } else {
-                    num_t *n = malloc(sizeof(num_t));
-                    *n = (num_t){
-                        .line = i,
-                        .column = j - length,
-                        .value = value,
-                        .length = length
-                    };
-                    vec_push_back(nums, n);
-                    value = 0;
-                    length = 0;
-                    state = IDLE;
-                    if (j >= line_len) break;
-                    continue;
-                }
-            }
-        }
-    }
-    return nums;
-}
-
-int is_symbol(char c) {
-    if (c >= '0' && c <= '9') return 0;
-    if (c == '.') return 0;
-    return 1;
-}
-
-int is_a_part(void *schema, num_t *num) {    
-    int line_len = vec_size(schema);
-    int col_len = strlen(vec_get(schema, 0));
-    for (int i = num->column - 1; i < num->column + num->length + 1; i++) {
-        if (num->line - 1 < 0) continue;
-        if (i < 0 || i >= col_len) continue;
-        if (is_symbol(((char*)vec_get(schema, num->line - 1))[i])) {
-            return 1;
-        }
-    }
-    for (int i = num->column - 1; i < num->column + num->length + 1; i++) {
-        if (num->line + 1 >= line_len) continue;
-        if (i < 0 || i >= col_len) continue;
-        if (is_symbol(((char*)vec_get(schema, num->line + 1))[i])) {
-            return 1;
-        }
-    }
-    if (num->column - 1 >= 0) {
-        if (is_symbol(((char*)vec_get(schema, num->line))[num->column - 1])) {
-            return 1;
-        }
-    }
-    if (num->column + num->length < col_len) {
-        char *line = vec_get(schema, num->line);
-        if (is_symbol(line[num->column + num->length])) {
-            return 1;
-        }
-    }
-    return 0;
-}
-
-int main() {
-    void *schema = read_input();
-    void *nums = parse_nums(schema);
-    int sum = 0;
-    for (int i = 0; i < vec_size(nums); i++) {
-        num_t *num = vec_get(nums, i);
-        if (is_a_part(schema, num)) {
-            sum += num->value;
-        }
-    }
-    printf("%d\n", sum);
-    return 0;
-}
diff --git a/advent-of-code/2023/03/part2.c b/advent-of-code/2023/03/part2.c
deleted file mode 100644
index a5ab825..0000000
--- a/advent-of-code/2023/03/part2.c
+++ /dev/null
@@ -1,149 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#include <assert.h>
-
-#include "vec.h"
-#include "str.h"
-#include "map.h"
-
-void* read_input() {
-    FILE* fp = fopen("./input", "r");
-    void *vec = new_vec();
-    while(1) {
-        char *line = fgetline(fp);
-        if (line == NULL) break;
-        char *stripped = str_strip(line);
-        if (strlen(stripped) == 0) break;
-        vec_push_back(vec, stripped);
-    }
-    return vec;
-}
-
-typedef struct {
-    int line;
-    int column;
-    int value;
-    int length;
-} num_t;
-
-char *compose_key(int x, int y) {
-    void* ss = new_ss();
-    ss_add(ss, "%d,%d", x, y);
-    return ss_cstr(ss);
-}
-
-void *parse_nums(void *schema) {
-    void *nums = new_vec();
-    int j = 0;
-    const int IN_NUM = 0, IDLE = 1;
-    int state = IDLE;
-    for (int i = 0; i < vec_size(schema); i++) {
-        char *line = vec_get(schema, i);
-        int line_len = strlen(line);
-        int value = 0;
-        int length = 0;
-        state = IDLE;
-        j = 0;
-        while (1) {
-            char c = '.';
-            if (j < line_len) c = line[j];
-            if (state == IDLE) {
-                if (isdigit(c)) {
-                    state = IN_NUM;
-                    continue;
-                } else {
-                    j++;
-                    if (j >= line_len) break;
-                    continue;
-                }
-            } else if (state == IN_NUM) {
-                if (isdigit(c)) {
-                    value = value * 10 + (c - '0'); 
-                    length++;
-                    j++;
-                    continue;
-                } else {
-                    num_t *n = malloc(sizeof(num_t));
-                    *n = (num_t){
-                        .line = i,
-                        .column = j - length,
-                        .value = value,
-                        .length = length
-                    };
-                    vec_push_back(nums, n);
-                    value = 0;
-                    length = 0;
-                    state = IDLE;
-                    if (j >= line_len) break;
-                    continue;
-                }
-            }
-        }
-    }
-    return nums;
-}
-
-char char_at(void *schema, int line, int column) {
-    char *buf = vec_get(schema, line);
-    return buf[column];
-}
-
-void mark_asterisks(void *asterisks, num_t *num, int x, int y) {
-    const char *key = compose_key(x, y);
-    void *num_list = dict_get(asterisks, key);
-    if (num_list == NULL) {
-        num_list = new_vec();
-        dict_set(asterisks, key, num_list);
-    }
-    vec_push_back(num_list, num);
-}
-
-void find_asterisks(void *schema, void *asterisks, num_t *num) {    
-    int line_len = vec_size(schema);
-    int col_len = strlen(vec_get(schema, 0));
-    for (int i = num->column - 1; i < num->column + num->length + 1; i++) {
-        if (num->line - 1 < 0) continue;
-        if (i < 0 || i >= col_len) continue;
-        char c = char_at(schema, num->line - 1, i);
-        if (c == '*') mark_asterisks(asterisks, num, num->line - 1, i);
-    }
-    for (int i = num->column - 1; i < num->column + num->length + 1; i++) {
-        if (num->line + 1 >= line_len) continue;
-        if (i < 0 || i >= col_len) continue;
-        char c = char_at(schema, num->line + 1, i);
-        if (c == '*') mark_asterisks(asterisks, num, num->line + 1, i);
-    }
-    if (num->column - 1 >= 0) {
-        char c = char_at(schema, num->line, num->column - 1);
-        if (c == '*') mark_asterisks(asterisks, num, num->line, num->column - 1);
-    }
-    if (num->column + num->length < col_len) {
-        char c = char_at(schema, num->line, num->column + num->length);
-        if (c == '*') mark_asterisks(asterisks, num, num->line, num->column + num->length);
-    }
-}
-
-int main() {
-    void *schema = read_input();
-    void *nums = parse_nums(schema);
-    int sum = 0;
-    void *asterisks = new_dict();
-    for (int i = 0; i < vec_size(nums); i++) {
-        num_t *num = vec_get(nums, i);
-        find_asterisks(schema, asterisks, num);
-    }
-    for (void *iter = dict_begin(asterisks);
-            iter != NULL;
-            iter = dict_next(asterisks, iter)) {
-        void *list = dict_iter_value(iter);
-        if (vec_size(list) == 2) {
-            num_t* n1 = vec_get(list, 0);
-            num_t* n2 = vec_get(list, 1);
-            sum += n1->value * n2->value;
-        }
-    }
-    printf("%d\n", sum);
-    return 0;
-}
diff --git a/advent-of-code/2023/04/1.rkt b/advent-of-code/2023/04/1.rkt
index a1edde2..5210420 100644
--- a/advent-of-code/2023/04/1.rkt
+++ b/advent-of-code/2023/04/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 (require "../lib/obj.rkt")
diff --git a/advent-of-code/2023/04/2.rkt b/advent-of-code/2023/04/2.rkt
index a9d751f..479f9d7 100644
--- a/advent-of-code/2023/04/2.rkt
+++ b/advent-of-code/2023/04/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require "../lib/utils.rkt")
 (require "../lib/obj.rkt")
diff --git a/advent-of-code/2023/05/1.rkt b/advent-of-code/2023/05/1.rkt
index f0ad5ed..411a36b 100755
--- a/advent-of-code/2023/05/1.rkt
+++ b/advent-of-code/2023/05/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define port (open-input-file "input"))
 
diff --git a/advent-of-code/2023/05/2.rkt b/advent-of-code/2023/05/2.rkt
index 5024c1e..9a0233f 100755
--- a/advent-of-code/2023/05/2.rkt
+++ b/advent-of-code/2023/05/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define port (open-input-file "input"))
 
diff --git a/advent-of-code/2023/06/1.rkt b/advent-of-code/2023/06/1.rkt
index ea0d013..92d0bf6 100644
--- a/advent-of-code/2023/06/1.rkt
+++ b/advent-of-code/2023/06/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define in (open-input-file "input"))
 
diff --git a/advent-of-code/2023/06/2.rkt b/advent-of-code/2023/06/2.rkt
index 5d124e0..cc381cf 100644
--- a/advent-of-code/2023/06/2.rkt
+++ b/advent-of-code/2023/06/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define in (open-input-file "input"))
 
diff --git a/advent-of-code/2023/07/part1.rkt b/advent-of-code/2023/07/1.rkt
index a22571d..635d6be 100644
--- a/advent-of-code/2023/07/part1.rkt
+++ b/advent-of-code/2023/07/1.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define input 
   (with-input-from-file "input"
diff --git a/advent-of-code/2023/07/part2.rkt b/advent-of-code/2023/07/2.rkt
index 50d9526..e88f949 100644
--- a/advent-of-code/2023/07/part2.rkt
+++ b/advent-of-code/2023/07/2.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (define input 
   (with-input-from-file "input"
diff --git a/advent-of-code/2023/lib/map.c b/advent-of-code/2023/lib/map.c
deleted file mode 100644
index 846033e..0000000
--- a/advent-of-code/2023/lib/map.c
+++ /dev/null
@@ -1,90 +0,0 @@
-#include "map.h"
-#include "rb_tree.h"
-
-#include <string.h>
-
-typedef int (*rb_cmp_t)(void*, void*);
-
-void* new_map(cmp_t compare) {
-    rb_tree_t *tree = malloc(sizeof(rb_tree_t));
-    rb_cmp_t cmp = (rb_cmp_t)compare;
-    *tree = (rb_tree_t){NULL, cmp, NULL};
-    return tree;
-}
-
-void map_set(void* self, void* key, void* value) {
-    node_entry_t *iter = rb_tree_find(self, &key);
-    if (iter == NULL) {
-        iter = malloc(sizeof(*iter));
-        iter->key = key;
-        iter->value = value;
-        rb_tree_insert(self, iter);
-    } else {
-        iter->value = value;
-    }
-}
-
-void* map_get(void* self, void* key) {
-    node_entry_t *iter = rb_tree_find(self, &key);
-    if (iter == NULL) return NULL;
-    return iter->value;
-}
-
-void map_erase(void* self, void* key) {
-    rb_tree_remove(self, key);
-}
-
-void* map_begin(void *self) {
-    return rb_tree_min(self);
-}
-
-void* map_next(void *self, void *iter) {
-    return rb_tree_next(self, iter);
-}
-
-void* map_iter_key(void* iter_) {
-    node_entry_t *iter = iter_;
-    return iter->key;
-}
-
-void* map_iter_value(void* iter_) {
-    node_entry_t *iter = iter_;
-    return iter->value;
-}
-
-static int dict_cmp(void **a, void** b) {
-    return strcmp(*a, *b);
-}
-void* new_dict() {
-    return new_map(dict_cmp);
-}
-
-void dict_set(void* self, const char *key, void* value) {
-    map_set(self, (void*)key, value);
-}
-
-void* dict_get(void* self, const char* key) {
-    return map_get(self, (void*)key);
-}
-
-void dict_erase(void* self, const char* key) {
-    map_erase(self, (void*)key);
-}
-
-void* dict_begin(void *self) {
-    return map_begin(self);
-}
-
-void* dict_next(void *self, void *iter) {
-    return map_next(self, iter);
-}
-
-const char* dict_iter_key(void* iter) {
-    return map_iter_key(iter);
-}
-
-void* dict_iter_value(void* iter) {
-    return map_iter_value(iter);
-}
-
-
diff --git a/advent-of-code/2023/lib/map.h b/advent-of-code/2023/lib/map.h
deleted file mode 100644
index c54048c..0000000
--- a/advent-of-code/2023/lib/map.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef MAP_H_
-#define MAP_H_
-
-#include "rb_tree.h"
-
-typedef struct {
-    rb_node_t node;
-    void *key;
-    void *value;
-} node_entry_t;
-typedef int (*cmp_t)(void** a, void** b);
-
-void* new_map(cmp_t compare);
-void map_set(void* self, void* key, void* value);
-void* map_get(void* self, void* key);
-void map_erase(void* self, void* key);
-
-void* map_begin(void *self);
-void* map_next(void *self, void *iter);
-void* map_iter_key(void* iter);
-void* map_iter_value(void* iter);
-
-void* new_dict();
-void dict_set(void* self, const char *key, void* value);
-void* dict_get(void* self, const char* key);
-void dict_erase(void* self, const char* key);
-
-void* dict_begin(void *self);
-void* dict_next(void *self, void *iter);
-const char* dict_iter_key(void* iter);
-void* dict_iter_value(void* iter);
-
-#endif
diff --git a/advent-of-code/2023/lib/obj.rkt b/advent-of-code/2023/lib/obj.rkt
index 9217976..578ea36 100644
--- a/advent-of-code/2023/lib/obj.rkt
+++ b/advent-of-code/2023/lib/obj.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (provide obj-maker
          obj-set
diff --git a/advent-of-code/2023/lib/rb_tree.c b/advent-of-code/2023/lib/rb_tree.c
deleted file mode 100644
index 5aa7905..0000000
--- a/advent-of-code/2023/lib/rb_tree.c
+++ /dev/null
@@ -1,378 +0,0 @@
-// Copyright (C) 2023 Mistivia <i@mistivia.com>
-// Licensed under GPLv3. See LICENSE for details.
-
-/*
- * Copyright 2002 Niels Provos <provos@citi.umich.edu>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "rb_tree.h"
-
-#define RED 1
-#define BLACK 0
-
-static rb_node_t *rb_tree_minmax(rb_tree_t *, int);
-void *rb_tree_min(rb_tree_t *head) { return rb_tree_minmax(head, -1); }
-void *rb_tree_max(rb_tree_t *head) { return rb_tree_minmax(head, 1); }
-
-void *rb_tree_left(void *node) {
-    rb_node_t *elm = node;
-    if (node == NULL) return NULL;
-    return elm->entry.rbe_left;
-}
-void *rb_tree_right(void *node) {
-    rb_node_t *elm = node;
-    if (node == NULL) return NULL;
-    return elm->entry.rbe_right;
-}
-void *rb_tree_parent(void *node) {
-    rb_node_t *elm = node;
-    if (node == NULL) return NULL;
-    return elm->entry.rbe_parent;
-}
-
-static void augment(rb_tree_t *head, rb_node_t *elm) {
-    if (head->augment != NULL) head->augment(elm);
-}
-
-static void rb_tree_insert_color(rb_tree_t *head, rb_node_t *elm);
-static void rb_tree_remove_color(rb_tree_t *head, rb_node_t *parent,
-                                 rb_node_t *elm);
-
-static void rotate_left(rb_tree_t *head, rb_node_t *elm) {
-    rb_node_t *tmp = elm->entry.rbe_right;
-    if ((elm->entry.rbe_right = tmp->entry.rbe_left)) {
-        tmp->entry.rbe_left->entry.rbe_parent = elm;
-    }
-    augment(head, elm);
-    if ((tmp->entry.rbe_parent = elm->entry.rbe_parent)) {
-        if (elm == elm->entry.rbe_parent->entry.rbe_left)
-            elm->entry.rbe_parent->entry.rbe_left = tmp;
-        else
-            elm->entry.rbe_parent->entry.rbe_right = tmp;
-    } else {
-        head->rbh_root = tmp;
-    }
-    tmp->entry.rbe_left = elm;
-    elm->entry.rbe_parent = tmp;
-    augment(head, tmp);
-    if (tmp->entry.rbe_parent) {
-        augment(head, tmp->entry.rbe_parent);
-    }
-}
-
-static void rotate_right(rb_tree_t *head, rb_node_t *elm) {
-    rb_node_t *tmp = elm->entry.rbe_left;
-    if ((elm->entry.rbe_left = tmp->entry.rbe_right)) {
-        tmp->entry.rbe_right->entry.rbe_parent = elm;
-    }
-    augment(head, elm);
-    if ((tmp->entry.rbe_parent = elm->entry.rbe_parent)) {
-        if (elm == elm->entry.rbe_parent->entry.rbe_left)
-            elm->entry.rbe_parent->entry.rbe_left = tmp;
-        else
-            elm->entry.rbe_parent->entry.rbe_right = tmp;
-    } else {
-        head->rbh_root = tmp;
-    }
-    tmp->entry.rbe_right = elm;
-    elm->entry.rbe_parent = tmp;
-    augment(head, tmp);
-    if (tmp->entry.rbe_parent) {
-        augment(head, tmp->entry.rbe_parent);
-    }
-}
-
-static void rb_tree_insert_color(rb_tree_t *head, rb_node_t *elm) {
-    rb_node_t *parent, *gparent, *tmp;
-    while ((parent = elm->entry.rbe_parent) && parent->entry.rbe_color == 1) {
-        gparent = parent->entry.rbe_parent;
-        if (parent == gparent->entry.rbe_left) {
-            tmp = gparent->entry.rbe_right;
-            if (tmp && tmp->entry.rbe_color == 1) {
-                tmp->entry.rbe_color = BLACK;
-                parent->entry.rbe_color = BLACK;
-                gparent->entry.rbe_color = RED;
-                elm = gparent;
-                continue;
-            }
-            if (parent->entry.rbe_right == elm) {
-                rotate_left(head, parent);
-                tmp = parent;
-                parent = elm;
-                elm = tmp;
-            }
-            parent->entry.rbe_color = BLACK;
-            gparent->entry.rbe_color = RED;
-            rotate_right(head, gparent);
-        } else {
-            tmp = gparent->entry.rbe_left;
-            if (tmp && tmp->entry.rbe_color == 1) {
-                tmp->entry.rbe_color = BLACK;
-                parent->entry.rbe_color = BLACK;
-                gparent->entry.rbe_color = RED;
-                ;
-                elm = gparent;
-                continue;
-            }
-            if (parent->entry.rbe_left == elm) {
-                rotate_right(head, parent);
-                tmp = parent;
-                parent = elm;
-                elm = tmp;
-            }
-            parent->entry.rbe_color = BLACK;
-            gparent->entry.rbe_color = RED;
-            rotate_left(head, gparent);
-        }
-    }
-    head->rbh_root->entry.rbe_color = BLACK;
-}
-
-static void rb_tree_remove_color(rb_tree_t *head, rb_node_t *parent,
-                                 rb_node_t *elm) {
-    rb_node_t *tmp;
-    while ((elm == NULL || elm->entry.rbe_color == 0) &&
-           elm != head->rbh_root) {
-        if (parent->entry.rbe_left == elm) {
-            tmp = parent->entry.rbe_right;
-            if (tmp->entry.rbe_color == 1) {
-                tmp->entry.rbe_color = BLACK;
-                parent->entry.rbe_color = RED;
-                rotate_left(head, parent);
-                tmp = parent->entry.rbe_right;
-            }
-            if ((tmp->entry.rbe_left == NULL ||
-                 tmp->entry.rbe_left->entry.rbe_color == 0) &&
-                (tmp->entry.rbe_right == NULL ||
-                 tmp->entry.rbe_right->entry.rbe_color == 0)) {
-                tmp->entry.rbe_color = RED;
-                elm = parent;
-                parent = elm->entry.rbe_parent;
-            } else {
-                if (tmp->entry.rbe_right == NULL ||
-                    tmp->entry.rbe_right->entry.rbe_color == 0) {
-                    rb_node_t *oleft;
-                    if ((oleft = tmp->entry.rbe_left))
-                        oleft->entry.rbe_color = BLACK;
-                    tmp->entry.rbe_color = RED;
-                    rotate_right(head, tmp);
-                    tmp = parent->entry.rbe_right;
-                }
-                tmp->entry.rbe_color = parent->entry.rbe_color;
-                parent->entry.rbe_color = BLACK;
-                if (tmp->entry.rbe_right)
-                    tmp->entry.rbe_right->entry.rbe_color = BLACK;
-                rotate_left(head, parent);
-                elm = head->rbh_root;
-                break;
-            }
-        } else {
-            tmp = parent->entry.rbe_left;
-            if (tmp->entry.rbe_color == 1) {
-                tmp->entry.rbe_color = BLACK;
-                parent->entry.rbe_color = RED;
-                rotate_right(head, parent);
-                tmp = parent->entry.rbe_left;
-            }
-            if ((tmp->entry.rbe_left == NULL ||
-                 tmp->entry.rbe_left->entry.rbe_color == 0) &&
-                (tmp->entry.rbe_right == NULL ||
-                 tmp->entry.rbe_right->entry.rbe_color == 0)) {
-                tmp->entry.rbe_color = RED;
-                elm = parent;
-                parent = elm->entry.rbe_parent;
-            } else {
-                if (tmp->entry.rbe_left == NULL ||
-                    tmp->entry.rbe_left->entry.rbe_color == 0) {
-                    rb_node_t *oright;
-                    if ((oright = tmp->entry.rbe_right))
-                        oright->entry.rbe_color = BLACK;
-                    tmp->entry.rbe_color = RED;
-                    rotate_left(head, tmp);
-                    tmp = parent->entry.rbe_left;
-                }
-                tmp->entry.rbe_color = parent->entry.rbe_color;
-                parent->entry.rbe_color = BLACK;
-                if (tmp->entry.rbe_left)
-                    tmp->entry.rbe_left->entry.rbe_color = BLACK;
-                rotate_right(head, parent);
-                elm = head->rbh_root;
-                break;
-            }
-        }
-    }
-    if (elm) elm->entry.rbe_color = BLACK;
-}
-
-void rb_tree_remove(rb_tree_t *head, void *elmv) {
-    rb_node_t *elm = elmv;
-    rb_node_t *child, *parent;
-    int color;
-    if (elm->entry.rbe_left == NULL)
-        child = elm->entry.rbe_right;
-    else if (elm->entry.rbe_right == NULL)
-        child = elm->entry.rbe_left;
-    else {
-        rb_node_t *old = elm, *left;
-        elm = elm->entry.rbe_right;
-        while ((left = elm->entry.rbe_left))
-            elm = left;
-        child = elm->entry.rbe_right;
-        parent = elm->entry.rbe_parent;
-        color = elm->entry.rbe_color;
-        if (child) child->entry.rbe_parent = parent;
-        if (parent) {
-            if (parent->entry.rbe_left == elm)
-                parent->entry.rbe_left = child;
-            else
-                parent->entry.rbe_right = child;
-            augment(head, parent);
-        } else
-            head->rbh_root = child;
-        if (elm->entry.rbe_parent == old) parent = elm;
-        elm->entry = old->entry;
-        if (old->entry.rbe_parent) {
-            if ((old->entry.rbe_parent)->entry.rbe_left == old)
-                (old->entry.rbe_parent)->entry.rbe_left = elm;
-            else
-                (old->entry.rbe_parent)->entry.rbe_right = elm;
-            augment(head, old->entry.rbe_parent);
-        } else
-            head->rbh_root = elm;
-        old->entry.rbe_left->entry.rbe_parent = elm;
-        if (old->entry.rbe_right) old->entry.rbe_right->entry.rbe_parent = elm;
-        if (parent) {
-            left = parent;
-            if (head->augment != NULL) {
-                do {
-                    augment(head, left);
-                } while ((left = left->entry.rbe_parent));
-            }
-        }
-        goto color;
-    }
-    parent = elm->entry.rbe_parent;
-    color = elm->entry.rbe_color;
-    if (child) child->entry.rbe_parent = parent;
-    if (parent) {
-        if (parent->entry.rbe_left == elm)
-            parent->entry.rbe_left = child;
-        else
-            parent->entry.rbe_right = child;
-        rb_node_t *goback = parent;
-        if (head->augment != NULL) {
-            do {
-                augment(head, goback);
-            } while ((goback = goback->entry.rbe_parent));
-        }
-    } else
-        head->rbh_root = child;
-color:
-    if (color == 0) rb_tree_remove_color(head, parent, child);
-}
-
-void *rb_tree_insert(rb_tree_t *head, void *elmv) {
-    rb_node_t *elm = elmv;
-    rb_node_t *tmp;
-    rb_node_t *parent = NULL;
-    int comp = 0;
-    tmp = head->rbh_root;
-    while (tmp) {
-        parent = tmp;
-        comp = head->cmp((void *)elm->content, (void *)parent->content);
-        if (comp < 0)
-            tmp = tmp->entry.rbe_left;
-        else if (comp > 0)
-            tmp = tmp->entry.rbe_right;
-        else
-            return tmp;
-    }
-    elm->entry.rbe_parent = parent;
-    elm->entry.rbe_left = elm->entry.rbe_right = NULL;
-    elm->entry.rbe_color = RED;
-    if (parent != NULL) {
-        if (comp < 0)
-            parent->entry.rbe_left = elm;
-        else
-            parent->entry.rbe_right = elm;
-        rb_node_t *goback = parent;
-        if (head->augment != NULL) {
-            do {
-                augment(head, goback);
-            } while ((goback = goback->entry.rbe_parent));
-        }
-    } else
-        head->rbh_root = elm;
-    rb_tree_insert_color(head, elm);
-    return (NULL);
-}
-
-void *rb_tree_find(rb_tree_t *head, void *key) {
-    rb_node_t *tmp = head->rbh_root;
-    int comp;
-    while (tmp) {
-        comp = head->cmp(key, (void *)tmp->content);
-        if (comp < 0)
-            tmp = tmp->entry.rbe_left;
-        else if (comp > 0)
-            tmp = tmp->entry.rbe_right;
-        else
-            return tmp;
-    }
-    return (NULL);
-}
-
-void *rb_tree_next(rb_tree_t *head, void *elmv) {
-    rb_node_t *elm = elmv;
-    if (elm->entry.rbe_right) {
-        elm = elm->entry.rbe_right;
-        while (elm->entry.rbe_left)
-            elm = elm->entry.rbe_left;
-    } else {
-        if (elm->entry.rbe_parent &&
-            (elm == (elm->entry.rbe_parent)->entry.rbe_left))
-            elm = elm->entry.rbe_parent;
-        else {
-            while (elm->entry.rbe_parent &&
-                   (elm == (elm->entry.rbe_parent)->entry.rbe_right))
-                elm = elm->entry.rbe_parent;
-            elm = elm->entry.rbe_parent;
-        }
-    }
-    return elm;
-}
-
-static rb_node_t *rb_tree_minmax(rb_tree_t *head, int val) {
-    rb_node_t *tmp = head->rbh_root;
-    rb_node_t *parent = NULL;
-    while (tmp) {
-        parent = tmp;
-        if (val < 0)
-            tmp = tmp->entry.rbe_left;
-        else
-            tmp = tmp->entry.rbe_right;
-    }
-    return parent;
-};
-
diff --git a/advent-of-code/2023/lib/rb_tree.h b/advent-of-code/2023/lib/rb_tree.h
deleted file mode 100644
index 2096ff6..0000000
--- a/advent-of-code/2023/lib/rb_tree.h
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright (C) 2023 Mistivia <i@mistivia.com>
-// Licensed under GPLv3. See LICENSE for details.
-
-/*
- * Copyright 2002 Niels Provos <provos@citi.umich.edu>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef RB_TREE_H_
-#define RB_TREE_H_
-
-#include <stdlib.h>
-
-struct rb_node {
-    struct {
-        struct rb_node *rbe_left;
-        struct rb_node *rbe_right;
-        struct rb_node *rbe_parent;
-        int rbe_color;
-    } entry;
-    char content[0];
-};
-typedef struct rb_node rb_node_t;
-
-struct rb_tree {
-    rb_node_t *rbh_root;
-    int (*cmp)(void *k1, void *k2);
-    void (*augment)(void *elm);
-};
-typedef struct rb_tree rb_tree_t;
-
-void rb_tree_remove(rb_tree_t *, void *iter);
-
-// return a iterator
-void *rb_tree_insert(rb_tree_t *, void *treenode);
-void *rb_tree_find(rb_tree_t *, void *val);
-void *rb_tree_next(rb_tree_t *, void *iter);
-void *rb_tree_min(rb_tree_t *);
-void *rb_tree_max(rb_tree_t *);
-void *rb_tree_left(void *node);
-void *rb_tree_right(void *node);
-void *rb_tree_parent(void *node);
-
-#endif
diff --git a/advent-of-code/2023/lib/str.c b/advent-of-code/2023/lib/str.c
deleted file mode 100644
index 511e45b..0000000
--- a/advent-of-code/2023/lib/str.c
+++ /dev/null
@@ -1,143 +0,0 @@
-// Copyright (C) 2023 Mistivia <i@mistivia.com>
-// Licensed under GPLv3. See LICENSE for details.
-
-#include "str.h"
-
-#include <ctype.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "vec.h"
-
-void *str_split(const char *str, char delim) {
-    void* ret = new_vec();
-
-    if (str == NULL) return NULL;
-    if (*str == '\n') {
-        return ret;
-    }
-    int count = 0;
-    const char *begin = str;
-    for (const char *p = str; *p != '\0'; p++) {
-        if (*p != delim && !(delim == '\0' && isspace(*p))) {
-            continue;
-        }
-        int size = p - begin;
-        if (size > 0) count++;
-    }
-    count++;
-
-    begin = str;
-    int i = 0;
-    bool finished = false;
-    for (const char *p = str; !finished; p++) {
-        if (*p == '\0') finished = true;
-        if (*p != delim && *p != '\0' && !(delim == '\0' && isspace(*p))) {
-            continue;
-        }
-        int size = p - begin;
-        if (size == 0) {
-            begin = p + 1;
-            continue;
-        }
-        char *buf = malloc(sizeof(char) * (size + 1));
-        buf[size] = '\0';
-        memcpy(buf, begin, size * sizeof(char));
-        begin = p + 1;
-        vec_push_back(ret, buf);
-    }
-    return ret;
-}
-
-char *str_strip(const char *str) {
-    if (str == NULL) return NULL;
-    int len = strlen(str);
-    const char *begin = str;
-    const char *end = str + len - 1;
-    while (isspace(*begin) && begin < end) {
-        begin++;
-    }
-    while (isspace(*end) && end >= begin) {
-        end--;
-    }
-    len = end - begin + 1;
-    char *buf = malloc(sizeof(char) * (len) + 1);
-    buf[len] = '\0';
-    memcpy(buf, begin, len);
-    return buf;
-}
-
-typedef struct {
-    size_t size;
-    size_t cap;
-    char *buf;
-} str_builder_t;
-
-// string stream
-void* new_ss() {
-    str_builder_t *self = malloc(sizeof(str_builder_t));
-    *self = (str_builder_t){.size = 0, .cap = 16};
-    self->buf = malloc(sizeof(char) * 17);
-    return self;
-}
-
-static void ss_reserve(str_builder_t *self, int extra) {
-    if (self->size + extra <= self->cap) {
-        return;
-    }
-    int new_cap = (self->size + extra) * 2;
-    self->buf = realloc(self->buf, new_cap + 1);
-    memset(self->buf + self->cap, 0, new_cap - self->cap + 1);
-    self->cap = new_cap;
-}
-
-void ss_add(void *self_, char *format, ...) {
-    str_builder_t *self = self_;
-    va_list va1;
-    va_list va2;
-    va_start(va1, format);
-    va_copy(va2, va1);
-    int size = vsnprintf(NULL, 0, format, va1);
-    ss_reserve(self, size);
-    vsnprintf(self->buf + self->size, self->cap - self->size + 1, format, va2);
-    self->size += size;
-}
-
-void ss_addc(void *self_, char c) {
-    str_builder_t *self = self_;
-    ss_reserve(self, 1);
-    self->buf[self->size] = c;
-    self->size++;
-}
-
-char *ss_cstr(void *self_) {
-    str_builder_t *self = self_;
-    return self->buf;    
-}
-
-size_t ss_size(void *self_) {
-    str_builder_t *self = self_;
-    return self->size;
-}
-
-char *fgetline(FILE *fp) {
-    void *ss = new_ss();
-    while (true) {
-        int c = fgetc(fp);
-        if (c == EOF && ss_size(ss) == 0) return NULL;
-        if (c != EOF) ss_addc(ss, c);
-        if (c == EOF || c == '\n') return ss_cstr(ss);
-    }
-    return NULL;
-}
-
-int fpeek(FILE *fp) {
-    int c = fgetc(fp);
-    if (c == EOF) return c;
-    ungetc(c, fp);
-    return c;
-}
diff --git a/advent-of-code/2023/lib/str.h b/advent-of-code/2023/lib/str.h
deleted file mode 100644
index 214e297..0000000
--- a/advent-of-code/2023/lib/str.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (C) 2023 Mistivia <i@mistivia.com>
-// Licensed under GPLv3. See LICENSE for details.
-
-#ifndef DYMC_STR_H_
-#define DYMC_STR_H_
-
-#include <stdio.h>
-#include <stddef.h>
-
-char *str_strip(const char *str);
-void* str_split(const char *str, char delim);
-
-
-// string stream
-void* new_ss();
-void ss_add(void *self, char *format, ...);
-void ss_addc(void *self, char c);
-char *ss_cstr(void *self);
-size_t ss_size(void* self);
-
-char *fgetline(FILE *fp);
-int fpeek(FILE *fp);
-
-#endif
diff --git a/advent-of-code/2023/lib/utils.rkt b/advent-of-code/2023/lib/utils.rkt
index 946bb86..40c6f6b 100644
--- a/advent-of-code/2023/lib/utils.rkt
+++ b/advent-of-code/2023/lib/utils.rkt
@@ -1,7 +1,14 @@
-#lang racket
+#lang racket/base
 
 (provide get-lines
-         enumerate)
+         enumerate
+         repeat)
+
+(define (repeat n e)
+  (let loop ((i 0) (ret '()))
+    (if (>= i n)
+      ret
+      (loop (+ 1 i) (cons e ret)))))
 
 (define (get-lines fp)
   (let loop ((lines '()))
diff --git a/advent-of-code/2023/lib/vec.c b/advent-of-code/2023/lib/vec.c
deleted file mode 100644
index c3d8a0a..0000000
--- a/advent-of-code/2023/lib/vec.c
+++ /dev/null
@@ -1,72 +0,0 @@
-#include "vec.h"
-
-#include <string.h>
-#include "stdlib.h"
-
-struct vec {
-    size_t length;
-    size_t capacity;
-    void** buf;
-};
-
-static void vec_enlarge(struct vec* self) {
-    self->buf = realloc(self->buf, self->capacity * sizeof(void*) * 2);
-    self->capacity = self->capacity * 2;
-}
-
-void *new_vec() {
-    struct vec* vec = malloc(sizeof(struct vec));
-    vec->length = 0;
-    vec->capacity = 16;
-    vec->buf = malloc(16 * sizeof(void*));
-    return vec;
-}
-
-void vec_push_back(void *self_, void* obj) {
-    struct vec *self = self_;
-    if (self->length == self->capacity) vec_enlarge(self);
-    self->buf[self->length] = obj;
-    self->length++;
-}
-
-void* vec_get(void *self_, size_t n) {
-    struct vec *self = self_;
-    if (n < 0 || n >= self->length) return NULL;
-    return self->buf[n];
-}
-
-
-void vec_erase(void *self_, size_t n) {
-    struct vec *self = self_;
-    if (self->length <= n) {
-        return;
-    }
-    memmove(self->buf + n, self->buf + n + 1, (self->length - n - 1) * sizeof(void*));
-    self->length--;
-}
-
-size_t vec_size(void *self_) {
-    struct vec *self = self_;
-    return self->length;
-}
-
-void vec_reserve(void *self_, size_t n) {
-    struct vec *self = self_;
-    if (n <= self->capacity) {
-        return;
-    }
-    self->buf = malloc(sizeof(void*) * n);
-    self->capacity = n;
-}
-
-void vec_insert(void *self_, size_t pos, void *obj) {
-    struct vec *self = self_;
-    if (self->length == self->capacity) {
-        vec_enlarge(self);
-    }
-    if (pos > self->length || pos < 0) return;
-    memmove(self->buf + pos + 1, self->buf + pos, sizeof(void*) * (self->length - pos));
-    self->buf[pos] = obj;
-    self->length++;
-}
-
diff --git a/advent-of-code/2023/lib/vec.h b/advent-of-code/2023/lib/vec.h
deleted file mode 100644
index 5778689..0000000
--- a/advent-of-code/2023/lib/vec.h
+++ /dev/null
@@ -1,15 +0,0 @@
-#ifndef VEC_H_ 
-#define VEC_H_ 
-
-#include <stddef.h>
-
-void *new_vec();
-void vec_push_back(void *self, void* obj);
-void* vec_get(void *self, size_t n);
-size_t vec_length(void *self);
-void vec_erase(void *self, size_t n);
-size_t vec_size(void* self);
-void vec_reserve(void* self, size_t n);
-void vec_insert(void* self, size_t pos, void* obj);
-
-#endif
diff --git a/codewars/6-kyu/pyramid-array/solution.rkt b/codewars/6-kyu/pyramid-array/solution.rkt
index 0d6a00b..4973db9 100644
--- a/codewars/6-kyu/pyramid-array/solution.rkt
+++ b/codewars/6-kyu/pyramid-array/solution.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 ;; https://www.codewars.com/kata/515f51d438015969f7000013
 
diff --git a/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt b/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt
index 6859107..a8172a1 100644
--- a/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt
+++ b/codewars/7-kyu/a-rule-of-divisibility-by-7/solution.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 ;; https://www.codewars.com/kata/55e6f5e58f7817808e00002e