Path Sum.java

https://leetcode.com/problems/path-sum
public class path_sum { 
 public class TreeNode {
     int val;
     TreeNode left;
     TreeNode right;
     TreeNode() {}
     TreeNode(int val) { this.val = val; }
     TreeNode(int val, TreeNode left, TreeNode right) {
         this.val = val;
         this.left = left;
         this.right = right;
     }
 }
 
class Solution {
    public boolean hasPathSum(TreeNode root, int targetSum) {
        if(root == null){
            return false;
        }   
        if(root.left == null && root.right == null){
            return root.val - targetSum == 0;
        }
        boolean left = hasPathSum(root.left, targetSum-root.val);
        boolean right = hasPathSum(root.right, targetSum-root.val);
        return left || right;
    }
}
}