Leetcode Same Tree

题意：判断两棵树是否相等。

思路：DFS。

class Solution {
public:
bool isSameTree(TreeNode* p, TreeNode* q) {
if(p == NULL && q == NULL) return true;
if(p == NULL && q != NULL) return false;
if(p != NULL && q == NULL) return false;

if(p->val != q->val) return false;

bool leftmark = false;
bool rightmark = false;
if(p->left) {
if(q ->left) leftmark = isSameTree(p->left, q->left);
else leftmark = false;
}
else {
if(q->left) leftmark = false;
else leftmark = true;
}

if(p->right) {
if(q->right) rightmark = isSameTree(p->right, q->right);
else rightmark = false;
}
else {
if(q->right) rightmark = false;
else rightmark = true;
}

if(leftmark && rightmark) return true;
else return false;
}
};