Leetcode 100 : same Tree

Leetcode—100

same Tree

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.

【题目大意】给定两棵树，判断是不是相同
【解法】同时便利两棵树，遇到树的结构或者节点值不一样，直接返回false
【AC代码】

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
    if(p == NULL && q == NULL){
        return true;
    }
    else if(p == NULL && q != NULL){
        return false;
    }
    else if(p != NULL && q == NULL){
        return false;
    }
    else{
        if(p ->val == q ->val){
            return (isSameTree(p ->left, q ->left) && isSameTree(p ->right, q ->right));
        }
        else{
            return false;
        }
    }
}