From 20ed8de3ff9da4e1e1a056035d2c03078b1b48cb Mon Sep 17 00:00:00 2001
From: 201625010219 <43445842+201625010219@users.noreply.github.com>
Date: Wed, 7 Nov 2018 12:02:05 +0800
Subject: [PATCH] =?UTF-8?q?=E7=AE=80=E7=AE=80=E5=8D=95=E5=8D=95=20add=20li?=
 =?UTF-8?q?st.c?=
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判断链表是不是回环链表
---
 list.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 list.c

diff --git a/list.c b/list.c
new file mode 100644
index 0000000..50deb53
--- /dev/null
+++ b/list.c
@@ -0,0 +1,31 @@
+bool isPalindrome(struct ListNode* head) {
+        struct ListNode *point1, *point2, *point3;
+        point3 = point2 = head;
+        point1 = NULL;
+        long int sum = 0;
+        int n = 1;
+        if(head == NULL || head->next == NULL)
+            return true;
+        while(point3->next != NULL)//��һ�α�����ȡֵ������
+        {
+            sum += n*point3->value;
+            n++;
+            point3 = point3->next;
+            point2->next = point1; //��������һ���ڵ��ÿգ���Ϊ���ú��һ����������һ��
+            point1 = point2;
+            point2 = point3;
+        }
+        sum += n*point3->value;
+        point2->next = point1;
+        n = 1;
+        while(point2 != NULL)//�ڶ��α���
+        {
+            sum -= n*point2->value;
+            n++;
+            point2 = point2->next;
+        }
+        if(sum == 0)
+            return true;
+        else
+            return false;
+    }
\ No newline at end of file