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.
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 if(!p && !q) 14 return true; 15 else if(!p || !q) 16 return false; 17 else if(p->val != q->val) 18 return false; 19 else 20 return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right); 21 } 22 };
递归。