Data commit

Task/Equilibrium-index/C/equilibrium-index.c

@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int list[] = {-7, 1, 5, 2, -4, 3, 0};
+
+int eq_idx(int *a, int len, int **ret)
+{
+	int i, sum, s, cnt;
+	/* alloc long enough: if we can afford the original list,
+	 * we should be able to afford to this.  Beats a potential
+         * million realloc() calls.  Even if memory is a real concern,
+         * there's no garantee the result is shorter than the input anyway */
+        cnt = s = sum = 0;
+	*ret = malloc(sizeof(int) * len);
+
+	for (i = 0; i < len; i++)
+                sum += a[i];
+
+	for (i = 0; i < len; i++) {
+		if (s * 2 + a[i] == sum) {
+			(*ret)[cnt] = i;
+                        cnt++;
+                }
+		s += a[i];
+	}
+
+        /* uncouraged way to use realloc since it can leak memory, for example */
+	*ret = realloc(*ret, cnt * sizeof(int));
+
+	return cnt;
+}
+
+int main()
+{
+	int i, cnt, *idx;
+	cnt = eq_idx(list, sizeof(list) / sizeof(int), &idx);
+
+	printf("Found:");
+	for (i = 0; i < cnt; i++)
+                printf(" %d", idx[i]);
+	printf("\n");
+
+	return 0;
+}