LeetCode: Path Sum Solution

Approach

Subtract

by during traversal

When reaching leaf node, if

is equal to then there exist a path

Implementation

1var hasPathSum = function (root, targetSum) {
2  if (!root) return false
3  if (!root.left && !root.right) return root.val === targetSum
4  targetSum -= root.val
5  return hasPathSum(root.left, targetSum) || hasPathSum(root.right, targetSum)
6}

References

Original problem

Similar problems

Path Sum II

Binary Tree Maximum Path Sum

Sum Root to Leaf Numbers

Path Sum III

Path Sum IV