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.

/**
* 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&&!q)
return true;
else if (p&&!q)
return false;
else if (!p&&q)
return false;
else
{
if (p->val != q->val)
return false;
else
return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
}
}
};