112. 路径总和

package leetcode;

public class LeetCode {
    public static void main(String[] args) {
    }
}

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;
        }

        return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val);
    }
}

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode(int x) {
        val = x;
    }
}