BiruLyu
5/30/2017 - 2:33 AM

112. Path Sum(#1).java

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