refactor from c to racket

10 files changed, 10 insertions, 822 deletions

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