112.md

112. Path Sum

Solution 1

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public boolean hasPathSum(TreeNode root, int sum) {
        if (root == null)
            return false;
        if (root.left == null && root.right == null)
            return root.val == sum;
        boolean ans1 = hasPathSum(root.left, sum - root.val);
        boolean ans2 = hasPathSum(root.right, sum - root.val);
        return ans1 || ans2;
    }
}