Swap Nodes in Pairs Problem

Swap Nodes in Pairs Problem — ExecCode Medium DSA Practice

Solve the Swap Nodes in Pairs problem on ExecCode. Free online medium DSA practice in Arrays - Basics. Write and run code in Java, C++, Python — no signup required to run.

Problem description

Given a linked list, swap every two adjacent nodes and return its head. You must solve without modifying values — only nodes themselves may be changed.

Examples

Input head = [1, 2, 3, 4]; Output [2, 1, 4, 3]

Constraints

0 ≤ n ≤ 100 0 ≤ Node.val ≤ 100

Practice Swap Nodes in Pairs free on ExecCode. Browse DSA problems, topic map, and placement guides.