[面试真题] LeetCode：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.
广度优先遍历，考察两棵树中每一个的值以及左右孩子的值是否相等。
Program Runtime: 8 milli secs
1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 bool isSameTree(TreeNode *p, TreeNode *q) { 13 // Start typing your C/C++ solution below 14 // DO NOT write int main() function 15 if(q == p){ 16 return true; 17 } 18 queue<TreeNode*> qq, qp; 19 if(NULL == p && NULL == q){ 20 return true; 21 }else if(NULL != p && NULL != q){ 22 qq.push(q); 23 qp.push(p); 24 }else{ 25 return false; 26 } 27 while(qq.size() != 0 && qp.size() != 0){ 28 TreeNode *curp = qp.front(); 29 qp.pop(); 30 TreeNode *curq = qq.front(); 31 qq.pop(); 32 if(curq->val != curp->val){ 33 return false; 34 } 35 if(curp->left && curq->left) { 36 if(curp->left->val != curq->left->val){ 37 return false; 38 } 39 qp.push(curp->left); 40 qq.push(curq->left); 41 }else if(curp->left != NULL && curq->left == NULL){ 42 return false; 43 }else if(curp->left == NULL && curq->left != NULL){ 44 return false; 45 } 46 if(curp->right && curq->right) { 47 if(curp->right->val != curq->right->val){ 48 return false; 49 } 50 qp.push(curp->right); 51 qq.push(curq->right); 52 }else if(curp->right != NULL && curq->right == NULL){ 53 return false; 54 }else if(curp->right == NULL && curq->right != NULL){ 55 return false; 56 } 57 } 58 if(qq.size() != 0 || qp.size() != 0){ 59 return false; 60 } 61 return true; 62 } 63 };
