package com.leetcode; public class MergeTwoBinaryTrees { class Solution { public TreeNode mergeTrees(TreeNode t1, TreeNode t2) { return merge(t1,t2); } public TreeNode merge(TreeNode t1 , TreeNode t2){ if(t1 == null && t2 == null) return null; if(t1 ==null) return t2; if(t2 == null) return t1; TreeNode node = new TreeNode(t1.val + t2.val); node.left = merge(t1.left,t2.left); node.right = merge(t1.right,t2.right); return node; } } 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; } } }