114. Flatten Binary Tree to Linked List
My accepted JavaScript solution to LeetCode problem 114, Flatten Binary Tree to Linked List, running in 0ms.
- Difficulty: Medium
- JavaScript
- Runtime 0ms
- Memory 55.2MB
- Updated
Read the problem on LeetCode View on GitHub
The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.
JavaScript
Accepted on LeetCode — runtime 0ms, memory 55.2MB, accepted 2025-12-24.
/**
* @param {TreeNode} root
* @return {void} Do not return anything, modify root in-place instead.
*/
var flatten = function(root) {
let curr = root;
while (curr) {
if (curr.left) {
// Find rightmost node in left subtree
let prev = curr.left;
while (prev.right) {
prev = prev.right;
}
// Connect rightmost to current's right subtree
prev.right = curr.right;
// Move left subtree to right
curr.right = curr.left;
curr.left = null;
}
curr = curr.right;
}
};