2026/02/27

[LeetCode] 206. Reverse Linked List

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/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution {
public:
  ListNode* reverseList(ListNode* head) {
    ListNode* prevNode = nullptr;
    ListNode* nextNode = nullptr;
    ListNode* curNode = head;
    while (curNode != nullptr) {
      nextNode = curNode->next;
      curNode->next = prevNode;
      prevNode = curNode;
      curNode = nextNode;
    }
    return prevNode;
  }
};