Leetcode algorithm refers to offer 24 Reverse linked list

Topic link ： The finger of the sword Offer 24. Reverse a linked list

Ideas

Algorithm ： iteration
data structure ： Linked list
Ideas ： Classic linked list exercises . Create two pointers , A node that points to the current traversal cur, The other one points to the previous node pre, The processing flow is to transfer the current node's next Pointer to pre node , then pre Pointer pointing again cur node ,cur Then point to the next node to which the current node originally points .

Code

C++

class Solution {
    
public:
    ListNode* reverseList(ListNode* head) {
    
        ListNode *pre = nullptr, *cur = head;
        while (cur != nullptr) {
    
            ListNode *nxt = cur->next;
            cur->next = pre;
            pre = cur;
            cur = nxt;
        }
        return pre;
    }
};