stepsortX/leetcode-patterns/reverse-linked-list/solution.cpp at main · 1046prt/stepsortX · GitHub

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// Stepsort · Reverse Linked List
// Category: LeetCode Patterns
// Animated walkthrough: https://stepsort.prakashraj.me/algorithm/reverse-linked-list

#include <bits/stdc++.h>
using namespace std;

struct ListNode {
    int val;
    ListNode* next;
    ListNode(int v) : val(v), next(nullptr) {}
};

ListNode* reverseList(ListNode* head) {
    ListNode* prev = nullptr;
    ListNode* curr = head;
    while (curr) {
        ListNode* nxt = curr->next;
        curr->next = prev;
        prev = curr;
        curr = nxt;
    }
    return prev;
}

void printList(ListNode* head) {
    while (head) {
        cout << head->val;
        if (head->next) cout << " -> ";
        head = head->next;
    }
    cout << endl;
}

int main() {
    ListNode* head = new ListNode(1);
    head->next = new ListNode(2);
    head->next->next = new ListNode(3);
    head->next->next->next = new ListNode(4);
    head->next->next->next->next = new ListNode(5);
    printList(reverseList(head));
    return 0;
}