【LeetCode】100. Same Tree

LeetCode-100

Links:https://leetcode.com/problems/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.

思路：判断当前节点相等，左右子节点相同。

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(p==NULL && q==NULL){
            //都为空的情况
            return true;
        }
        if(p!=NULL && q!=NULL){
            //都不为空的情况
            if(p->val == q->val 
            && isSameTree(p->left,q->left)
            && isSameTree(p->right,q->right))
            {
                return true;
            }
        }
        return false;
    }
};

/**

* Definition for a binary tree node.

* struct TreeNode {

* int val;

* TreeNode *left;

* TreeNode *right;

* TreeNode(int x) : val(x), left(NULL), right(NULL) {}

* };

class Solution {

public:

bool isSameTree(TreeNode* p, TreeNode* q) {

if(p==NULL && q==NULL){

//都为空的情况

return true;

}

if(p!=NULL && q!=NULL){

//都不为空的情况

if(p->val == q->val

&& isSameTree(p->left,q->left)

&& isSameTree(p->right,q->right))

{

return true;

}

return false;

}

};

相同的可能性：

1.都为空（NULL）

2.当前节点相等，左右子节点相同。

【LeetCode】100. Same Tree

Tagged on: LeetCode