一、题目内容

二、题解

解法1：

思路

代码

public class Solution {
    public TreeNode mergeTrees (TreeNode t1, TreeNode t2) {
        // write code here
        if(t1!=null&&t2==null){
            return t1;
        }
        if(t1==null&&t2!=null){
            return t2;
        }
        if(t1!=null&t2!=null){
            t1.val += t2.val;
            t1.left = mergeTrees(t1.left,t2.left);
            t1.right = mergeTrees(t1.right,t2.right);
        }
        return t1;
    }
}