题目:
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
代码:
1---未简化
/**
* 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) {
bool b1 = false, b2 = false, b3 = false;
b1 = isSameTree(p->left, q->left);
b2 = (p->val == q->val);
b3 = isSameTree(p->right, q->right);
return b1&&b2&&b3;
}
else return false;
}
};
2---简化后
/**
* 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 isSameTree(p->left, q->left)&&isSameTree(p->right, q->right)&&(p->val == q->val);
}
else return false;
}
};
想法:
递归