题解 | #判断一个链表是否为回文结构#

/**
 * struct ListNode {
 *  int val;
 *  struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param head ListNode类 the head
 * @return bool布尔型
 */
bool isPail(struct ListNode* head ) {
    // write code here
    if (head == NULL || head->next == NULL)
        return head;
    struct ListNode* dummy = head;
    int len = 0;
    while (dummy != NULL) {
        len++;
        dummy = dummy->next;
    }
    int* arr = (int*)malloc(sizeof(int) * len);
    int i = 0;
    dummy = head;
    while (dummy != NULL) {
        arr[i++] = dummy->val;
        dummy = dummy->next;
    }
    int begin = 0;
    int end = len - 1;
    while (begin < end) {
        if (arr[begin] != arr[end])
            return false;
        begin++;
        end--;
    }
    return true;
}