init commit

archive/algorithm/leetcode/141.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+
+struct ListNode
+{
+    int val;
+    struct ListNode *next;
+};
+
+typedef int bool;
+#define true 1;
+#define false 0;
+
+bool hasCycle(struct ListNode *head)
+{
+    if (head == NULL)
+    {
+        return false;
+    }
+    struct ListNode *k = head->next, *m = head;
+    while (k != m)
+    {
+        if (m == NULL || k == NULL)
+        {
+            return false;
+        }
+        m = m->next;
+        k = k->next;
+        if (k == NULL)
+        {
+            return false;
+        }
+        k = k->next;
+    }
+    return true;
+}
+
+int main()
+{
+    struct ListNode *head = malloc(sizeof(struct ListNode)), *next = malloc(sizeof(struct ListNode)), *tmp;
+    head->val = 3;
+    head->next = next;
+    tmp = next;
+    next->val = 2;
+    next->next = malloc(sizeof(struct ListNode));
+    next = next->next;
+
+    next->val = 0;
+    next->next = malloc(sizeof(struct ListNode));
+    next = next->next;
+
+    next->val = -4;
+    next->next = NULL;
+
+    hasCycle(head);
+    return 0;
+}