[LeetCode]617. Merge Two Binary Trees

题目描述

思路

递归
t1为空 返回 t2
t2为空 返回t1
同时为空返回null
都存在则计算和返回

代码

#include <iostream>struct TreeNode {    int val;;    TreeNode* left;    TreeNode* right;    TreeNode(int x) : val(x), left(NULL), right(right) {}};class Solution {public:    TreeNode* mergeTrees(TreeNode* t1, TreeNode* t2) {        if (t1 == NULL) return t2;        if (t2 == NULL) return t1;        t1->val += t2->val;        t1->left = mergeTrees(t1->left, t2->left);        t1->right = mergeTrees(t1->right, t2->right);        return t1;    }};