Subtree of Another Tree @LeetCode
PROBLEM :
Given two non-empty binary trees s and t, check whether tree t has exactly the same structure and node values with a subtree of s. A subtree of s is a tree consists of a node in s and all of this node's descendants. The tree s could also be considered as a subtree of itself.
Example 1:
Given tree s:
3
/ \
4 5
/ \
1 2
Given tree t:
4
/ \
1 2
Return true, because t has the same structure and node values with a subtree of s.
Example 2:
Given tree s:
3
/ \
4 5
/ \
1 2
/
0
Given tree t:
4
/ \
1 2
Return false.
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SIMPLE c++ IMPLEMENTATION :
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/**
* 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 isSubtree(TreeNode* s, TreeNode* t) {
if(!s)
return false ;
bool curr=false ;
if(s->val==t->val)
curr=Check(s,t) ;
if(curr)
return true ;
else
return isSubtree(s->left,t)||isSubtree(s->right,t) ;
}
bool Check(TreeNode* org,TreeNode* copy){
if(!org&&!copy)
return true ;
if(!org||!copy)
return false ;
return (org->val==copy->val)&&(Check(org->left,copy->left)&&(Check(org->right,copy->right))) ;
}
};
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Given two non-empty binary trees s and t, check whether tree t has exactly the same structure and node values with a subtree of s. A subtree of s is a tree consists of a node in s and all of this node's descendants. The tree s could also be considered as a subtree of itself.
Example 1:
Given tree s:
3
/ \
4 5
/ \
1 2
Given tree t:
4
/ \
1 2
Return true, because t has the same structure and node values with a subtree of s.
Example 2:
Given tree s:
3
/ \
4 5
/ \
1 2
/
0
Given tree t:
4
/ \
1 2
Return false.
--------------------------------------------------------------------------------
SIMPLE c++ IMPLEMENTATION :
--------------------------------------------------------------------------------
/**
* 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 isSubtree(TreeNode* s, TreeNode* t) {
if(!s)
return false ;
bool curr=false ;
if(s->val==t->val)
curr=Check(s,t) ;
if(curr)
return true ;
else
return isSubtree(s->left,t)||isSubtree(s->right,t) ;
}
bool Check(TreeNode* org,TreeNode* copy){
if(!org&&!copy)
return true ;
if(!org||!copy)
return false ;
return (org->val==copy->val)&&(Check(org->left,copy->left)&&(Check(org->right,copy->right))) ;
}
};
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