24-01

include/advent_utility.h

@@ -9,7 +9,7 @@
 #define MIN(x, y) (x) < (y) ? (x) : (y)
 
 char *md5_str(const char *);
-
 Vector *string_to_int_vector(const char *input_string, const char *delim);
+int int_comp(const void *a, const void *b);
 
 #endif

src/2024/01.c

@@ -1,10 +1,58 @@
+#include <limits.h>
 #include <stdio.h>
-#include <stdlib.h>
 
 #include "lfinput.h"
+#include "advent_utility.h"
 
 void advent2024day01(void) {
-  char *input = get_input("input/2024/01");
-  printf("Solution for Day 01 of 2024 is not completed yet\n");
-  free(input);
+  size_t sz = 0;
+  char **input = get_lines("input/2024/01", &sz);
+  int a[sz];
+  int b[sz];
+  const char* errstr;
+
+  for (size_t i = 0; i < sz; i++) {
+    size_t sp_sz = 0;
+    char **sp = split(input[i], &sp_sz, "   ");
+
+    a[i] = (int)strtonum(sp[0], INT_MIN, INT_MAX, &errstr);
+    if (errstr != NULL) {
+      printf("ERR: %s\n", errstr);
+      free(sp);
+      break;
+    }
+
+    b[i] = (int)strtonum(sp[1], INT_MIN, INT_MAX, &errstr);
+    if (errstr != NULL) {
+      printf("ERR: %s\n", errstr);
+      free(sp);
+      break;
+    }
+    free(sp);
+  }
+
+  qsort(a, sz, sizeof(int), int_comp);
+  qsort(b, sz, sizeof(int), int_comp);
+
+  int p1 = 0;
+  for (size_t i = 0; i < sz; i++) {
+    p1 += abs(a[i] - b[i]);
+  }
+
+  printf("%d\n", p1);
+
+  int p2 = 0;
+  for (size_t i = 0; i < sz; i++) {
+    int c = 0;
+    for (size_t j = 0; j < sz; j++) {
+      if (a[i] == b[j]) {
+        ++c;
+      }
+    }
+    p2 += a[i] * c;
+  }
+
+  printf("%d\n", p2);
+
+  del_lines(input);
 }

src/advent_utility.c

@@ -51,3 +51,6 @@ Vector *string_to_int_vector(const char *input_string, const char* delim) {
     return v;
 }
 
+int int_comp(const void *a, const void *b) {
+    return *(int *) a - *(int *) b;
+}