day 5 part 2

2 files changed, 152 insertions, 2 deletions

diff --git a/05/Makefile b/05/Makefile
index a8f700f..7d325ba 100644
--- a/05/Makefile
+++ b/05/Makefile
@@ -1,10 +1,10 @@
 all: part1 part2
 
 part1: part1.c
-	gcc -g part1.c -o part1 -lalgds
+	gcc -Wall -g part1.c -o part1 -lalgds
 
 part2: part2.c
-	gcc -g part2.c -o part2 -lalgds
+	gcc -Wall -g part2.c -o part2 -lalgds
 
 1: part1
 	cat input | ./part1
diff --git a/05/part2.c b/05/part2.c
index e69de29..f7939f2 100644
--- a/05/part2.c
+++ b/05/part2.c
@@ -0,0 +1,150 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <algds/vec.h>
+#include <algds/str.h>
+#include <algds/sort.h>
+#include <stdlib.h>
+
+#define PANIC do { \
+    fprintf(stderr, "panic at %s:%d\n", __FILE__, __LINE__); \
+    abort(); \
+} while (0)
+
+void expect_char(char e) {
+    int c = fpeek(stdin);
+    if (c != e) {
+        PANIC;
+    }
+    fgetc(stdin);
+}
+
+void skip_space() {
+    while (1) {
+        int c = fpeek(stdin);
+        if (c == EOF) return;
+        if (isspace(c)) {
+            fgetc(stdin);
+        } else {
+            return;
+        }
+    }
+}
+
+bool string2long(const char *s, long *num) {
+    char *end;
+    errno = 0;
+    *num = strtol(s, &end, 10);
+    if (end == s) {
+        return false;
+    }
+    if (errno != 0) {
+        return false;
+    }
+    return true;
+}
+
+int64_t parse_integer() {
+    long ret;
+    StrBuilder sb;
+    StrBuilder_init(&sb);
+    while (1) {
+        int c = fpeek(stdin);
+        if (isdigit(c)) {
+            fgetc(stdin);
+            StrBuilder_append_char(&sb, c);
+        } else {
+            break;
+        }
+    }
+    if (strlen(sb.buf) == 0) {
+        PANIC;
+    }
+    StrBuilder_append_char(&sb, '\0');
+    if (!string2long(sb.buf, &ret)) {
+        PANIC;
+    }
+    free(sb.buf);
+    return ret;
+}
+
+typedef struct {
+    int64_t start;
+    int64_t end;
+} Range;
+
+void Range_show(Range self, FILE *fp) {
+    fprintf(fp, "%ld-%ld", self.start, self.end);
+}
+
+VECTOR_DEF(Range)
+VECTOR_IMPL(Range)
+
+Range parse_range() {
+    Range ret;
+    ret.start = parse_integer();
+    expect_char('-');
+    ret.end = parse_integer();
+    expect_char('\n');
+    return ret;
+}
+
+
+int Range_cmp(Range a, Range b) {
+    if (a.start < b.start) {
+        return -1;
+    } else if (a.start == b.start) {
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
+QSORT_DEF(Range)
+QSORT_IMPL(Range)
+
+int main() {
+    RangeVector ranges, unioned;
+    RangeVector_init(&ranges);
+    RangeVector_init(&unioned);
+    int c;
+    while (1) {
+        c = fpeek(stdin);
+        if (c == '\n') {
+            break;
+        } else if (isdigit(c)) {
+            Range r = parse_range();
+            RangeVector_push_back(&ranges, r);
+        } else {
+            PANIC;
+        }
+    }
+    expect_char('\n');
+    Range_qsort(ranges.buffer, RangeVector_len(&ranges));
+    if (RangeVector_len(&ranges) < 1) {
+        PANIC;
+    }
+    Range current = ranges.buffer[0];
+    for (int i = 1; i < RangeVector_len(&ranges); i++) {
+        if (ranges.buffer[i].start > current.end) {
+            RangeVector_push_back(&unioned, current);
+            current = ranges.buffer[i];
+            continue;
+        } else if (ranges.buffer[i].end > current.end) {
+            current.end = ranges.buffer[i].end;
+        }
+    }
+    RangeVector_push_back(&unioned, current);
+    long res = 0;
+    for (int i = 0; i < RangeVector_len(&unioned); i++) {
+        Range cur = unioned.buffer[i];
+        res += cur.end - cur.start + 1;
+    }
+    printf("%ld\n", res);
+
+    RangeVector_free(&ranges);
+    RangeVector_free(&unioned);
+    return 0;
+}
\ No newline at end of file