Data commit

Task/Longest-increasing-subsequence/C/longest-increasing-subsequence.c

@@ -0,0 +1,44 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct node {
+	int val, len;
+	struct node *next;
+};
+
+void lis(int *v, int len)
+{
+	int i;
+	struct node *p, *n = calloc(len, sizeof *n);
+	for (i = 0; i < len; i++)
+		n[i].val = v[i];
+
+	for (i = len; i--; ) {
+		// find longest chain that can follow n[i]
+		for (p = n + i; p++ < n + len; ) {
+			if (p->val > n[i].val && p->len >= n[i].len) {
+				n[i].next = p;
+				n[i].len = p->len + 1;
+			}
+		}
+	}
+
+	// find longest chain
+	for (i = 0, p = n; i < len; i++)
+		if (n[i].len > p->len) p = n + i;
+
+	do printf(" %d", p->val); while ((p = p->next));
+	putchar('\n');
+
+	free(n);
+}
+
+int main(void)
+{
+	int x[] = { 3, 2, 6, 4, 5, 1 };
+	int y[] = { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 };
+
+	lis(x, sizeof(x) / sizeof(int));
+	lis(y, sizeof(y) / sizeof(int));
+	return 0;
+}