Same Tree

Desicription

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:

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Input: 1 1
/ \ / \
2 3 2 3
[1,2,3], [1,2,3]
Output: true

Example 2:

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Input: 1 1
/ \
2 2
[1,2], [1,null,2]
Output: false

Example 3:

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Input: 1 1
/ \ / \
2 1 1 2
[1,2,1], [1,1,2]
Output: false

Solution

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/**
* 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)
return 1;
if(p == NULL || q == NULL)
return 0;
if(p->val == q->val)
return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
return 0;
}
};