100. Same Tree

题目原文

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

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思路

1. 为空判断
2. 若当前节点值相等且利用递归判断左子树与右子树均相等，则返回true，否则返回false

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代码

class Solution {public:    bool isSameTree(TreeNode* p, TreeNode* q) {        if(!p&&!q) return true;        else if(p&&!q) return false;        else if(!p&&q) return false;        else{            if((p->val)==(q->val)&&isSameTree(p->left,q->left)&&isSameTree(p->right,q->right)) return true;            return false;        }    }};