Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
Example 1:
Input: 1 1 / \ / \ 2 3 2 3 [1,2,3], [1,2,3] Output: true
Example 2:
Input: 1 1 / \ 2 2 [1,2], [1,null,2] Output: false
Example 3:
Input: 1 1 / \ / \ 2 1 1 2 [1,2,1], [1,1,2] Output: false
Subject to the effect:
Given two binary tree determines whether they are identical, and if their structures are the same node values, binary tree is the same.
understanding:
If the root node are empty, the same as the current sub-tree. Not the same as empty, it is different.
If the current node is the same value, the same as the current node, access their left and right subtrees.
++ Code C :
/** * 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!=NULL&&q==NULL)){ return false; } if(p->val==q->val){ return isSameTree(p->left,q->left) && isSameTree(p->right,q->right); } return false; } };
operation result:
When executed with: 4 MS memory consumption: 9.8 MB