---
tags: leetcode
---

# [206. Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/)
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# My Solution
## Solution 1: Iteration
### The Key Idea for Solving This Coding Question
### C++ Code

/**
 * 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 *newHead = nullptr;

        while (head != nullptr) {
            ListNode *x = head->next;
            head->next = newHead;
            newHead = head;
            head = x;
       }

        return newHead;
    }
};

### Time Complexity
### Space Complexity
## Solution 2: Recursion
### The Key Idea for Solving This Coding Question
### C++ Code

/**
 * 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) {
        if (head == nullptr) {
            return nullptr;
        }
        if (head->next == nullptr) {
            return head;
        }

        ListNode *p = reverseList(head->next);
        head->next->next = head;
        head->next = nullptr;

        return p;
    }
};

### Time Complexity
### Space Complexity
# Miscellaneous
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