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:递归,判断根结点是否相同,不同返回false,相同的话再递归判断左子树和右子树
/**
* 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==0){
return q==0;
}
if(q==0){
return false;
}
return (p->val==q->val) && isSameTree(p->left,q->left) && isSameTree(p->right,q->right);
}
};