题目:
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:
根据树的递归结构,递归判断当前结点、左子树、右子树是否相等。
程序:
/**
* 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 true;
else if(p != NULL&&q == NULL)
return false;
else if(p == NULL&&q != NULL)
return false;
else
return (p->val == q->val)&&isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
}
};