2015-10-18 10:42:52 +08:00

70 lines
1.8 KiB
C++

// Source : https://oj.leetcode.com/problems/same-tree/
// Author : Hao Chen
// Date : 2014-06-27
/**********************************************************************************
*
* 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 binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
Solution(){
srand(time(NULL));
}
bool isSameTree(TreeNode *p, TreeNode *q) {
if (random()%2){
return isSameTree1(p, q);
}
return isSameTree2(p, q);
}
bool isSameTree1(TreeNode *p, TreeNode *q) {
if(!p && !q) return true;
if(!p || !q) return false;
return (p->val == q->val) &&
isSameTree(p->left, q->left) &&
isSameTree(p->right, q->right);
}
bool isSameTree2(TreeNode *p, TreeNode *q) {
queue<TreeNode*> q1, q2;
q1.push(p);
q2.push(q);
while (q1.size()>0 && q2.size()>0 ){
TreeNode* p1 = q1.front();
q1.pop();
TreeNode* p2 = q2.front();
q2.pop();
if (!p1 && !p2) continue;
if (!p1 || !p2) return false;
if ( p1->val != p2->val) {
return false;
}
q1.push(p1->left);
q2.push(p2->left);
q1.push(p1->right);
q2.push(p2->right);
}
return true;
}
};