2020.02.26

Author: ws333666

LeetCode206.c

@@ -0,0 +1,20 @@
+/*************************************************************************
+    > File Name: LeetCode206.c
+    > Author: ws
+    > Mail: [email protected] 
+    > Created Time: 2020年02月26日 星期三 17时25分19秒
+ ************************************************************************/
+
+struct ListNoderever(struct ListNode *head) {
+	struct ListNode ret, *p = head, *q;
+	ret.next = NULL;
+	while (p) {
+		q = p->next;
+		p->next = ret.next;
+		ret.next = p;
+		p = q;
+	}
+	return ret.next;
+}
+
+

LeetCode234.c

@@ -0,0 +1,42 @@
+/*************************************************************************
+    > File Name: LeetCode234.c
+    > Author: ws
+    > Mail: [email protected] 
+    > Created Time: 2020年02月26日 星期三 17时28分45秒
+ ************************************************************************/
+
+
+int get_length(struct ListNode *head) {
+	int n = 0;
+	while (head) n += 1, head = head->next;
+	return n;
+}
+
+struct ListNode *get_node(struct ListNode *head, int ind) {
+	while (ind--) head = head->next;
+	return head;
+}
+
+struct ListNode *reverse(struct ListNode *head) {
+	struct ListNode ret, *p = head, *q;
+	ret.next = NULL;
+	while (p) {
+		q = p->next;
+		p->next = ret.next;
+		ret.next = p;
+		p = q;
+	}
+	return ret.next;
+}
+
+bool isPalindrome(struct ListNode *head) {
+	int len = get_length(head);
+	struct ListNode *p = head, *q = reverse(get_node(head, (len + 1) / 2));
+	while (q) {
+		if (p->val - q->val) return false;
+		p = p->next;
+		q = q->next;
+	}
+	return true;
+}
+