leetcode206-- list Flip

Reverse a singly linked list.

Example:

Input: l-> 2-> 3-> 4-> 5-> NULL
 Output: 5-> 4-> 3-> 2-> l-> NULL

Problem-solving ideas:

Starting from the head of the list, up three pointers to three adjacent elements, constantly changing direction between the link until a complete traversal of the list

Implementation code:

struct ListNode* reverseList(struct ListNode* head){
    struct ListNode* node = head;
    struct ListNode* cur = head;
    struct ListNode* pre = NULL;
    while(cur) { 
        cur = cur->next;
        node->next = pre;
        pre = node;
        node = cur;      
    }
    return pre;
}

operation result: