Leetcode 100. Same Tree

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

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

Example 1:

Input: 1 1
/ \ / \
2 3 2 3

[1,2,3], [1,2,3]

Output: true
Example 2:

Input: 1 1
/ \
2 2

[1,2], [1,null,2]

Output: false
Example 3:

Input: 1 1
/ \ / \
2 1 1 2

[1,2,1], [1,1,2]

Output: false。

该题判断两棵树是否一样

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