tasks a-s

Task/Remove-duplicate-elements/C/remove-duplicate-elements-3.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int icmp(const void *a, const void *b)
+{
+#define _I(x) *(int*)x
+	return _I(a) < _I(b) ? -1 : _I(a) > _I(b);
+#undef _I
+}
+
+/* filter items in place and return number of uniques.  if a separate
+   list is desired, duplicate it before calling this function */
+int uniq(int *a, int len)
+{
+	int i, j;
+	qsort(a, len, sizeof(int), icmp);
+	for (i = j = 0; i < len; i++)
+		if (a[i] != a[j]) a[++j] = a[i];
+	return j + 1;
+}
+
+int main()
+{
+	int x[] = {1, 2, 1, 4, 5, 2, 15, 1, 3, 4};
+	int i, len = uniq(x, sizeof(x) / sizeof(x[0]));
+	for (i = 0; i < len; i++) printf("%d\n", x[i]);
+
+	return 0;
+}