2015-03. Add advent_utility and libflint

src/2015/03.c

@@ -1,10 +1,74 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
+#include "set.h"
 #include "input.h"
+#include "advent_utility.h"
+
+static int part_two(char *input) {
+    int sx = 0, sy = 0, rx = 0, ry = 0, is_santa = 1;
+    int *x, *y;
+    char *c = input;
+
+    Set* houses = malloc(sizeof(Set));
+    set_init(houses, same_Point_v, free);
+
+    while (*c != '\0') {
+        if (is_santa) {
+            x = &sx;
+            y = &sy;
+        } else {
+            x = &rx;
+            y = &ry;
+        }
+        is_santa = is_santa == 1 ? 0 : 1;
+
+        switch (*c) {
+        case '^': ++(*y); break;
+        case 'v': --(*y); break;
+        case '>': ++(*x); break;
+        case '<': --(*x); break;
+        }
+        set_insert(houses, (void *) new_Point_p(*x, *y));
+        ++c;
+    }
+
+    int sz = (int)houses->size;
+    set_destroy(houses);
+
+    return sz;
+}
+
+static int part_one(char *input) {
+    int x = 0, y = 0;
+    char *c = input;
+
+    Set* houses = malloc(sizeof(Set));
+    set_init(houses, same_Point_v, free);
+
+    while (*c != '\0') {
+        switch (*c) {
+        case '^': ++y; break;
+        case 'v': --y; break;
+        case '>': ++x; break;
+        case '<': --x; break;
+        }
+        set_insert(houses, (void *) new_Point_p(x, y));
+        ++c;
+    }
+
+    int sz = (int)houses->size;
+    set_destroy(houses);
+
+    return sz;
+}
 
 void advent2015day03(void) {
   char *input = get_input("input/2015/03");
-  printf("Solution for Day 03 of 2015 is not completed yet\n");
+
+  printf("%d\n", part_one(input));
+  printf("%d\n", part_two(input));
+
   free(input);
 }