【LeetCode】100. 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.

递归调用：

/**
 * 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==NULL && q==NULL) return true;
        else if(p!=NULL && q!= NULL && p->val != q->val)
            return false;
        else if(p!=NULL && q== NULL)
            return false;
        else if(q!=NULL && p== NULL)
            return false;
        else return isSameTree(p->left,q->left)&& isSameTree(p->right,q->right);
        
    }
};