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;
}
}
}