---
tags: leetcode
---

# [92. Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/)
---
# My Solution
## 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* reverseBetween(ListNode* head, int left, int right) {
        if (left == right || !head->next) {
            return head;
        }

        ListNode *dummy = new ListNode(-1000, head), *prev = dummy;
        for (int i = 1; i < left; ++i) {
            prev = prev->next;
        }

        ListNode* curr = prev->next;
        while (left < right) {
            ListNode* tmp = curr->next;
            curr->next = tmp->next;
            tmp->next = prev->next;
            prev->next = tmp;
            ++left;
        }

        head = dummy->next;
        delete dummy;
        return head;
    }
};

## Time Complexity
## Space Complexity
# Miscellaneous
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# Test Cases

[1,2,3,4,5]
2
4

[5]
1
1

[3,5]
1
2

[1,2,3,4,5]
1
4

[1,2,3,4,5,6,7,8,9,10]
3
7

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