//100
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.
class Solution {
public:
bool isSameTree(TreeNode* p, TreeNode* q) {
//p,q may NULL
if(p==NULL && q==NULL){
return true;
}
if(p==NULL || q==NULL){
return false;
}
//p,q is not NULL,recursion
if(p->val == q->val){
bool left=isSameTree(p->left,q->left);
bool right=isSameTree(p->right,q->right);
return left && right;
} else{
return false;
}
}
};