題目描述
輸入兩棵二叉樹A,B,判斷B是不是A的子結構。(ps:我們約定空樹不是任意一個樹的子結構)
解題思路
class Solution {
bool isSubtree(TreeNode* pRootA, TreeNode* pRootB) {
if (pRootB == NULL) return true;
if (pRootA == NULL) return false;
if (pRootB->val == pRootA->val) {
return isSubtree(pRootA->left, pRootB->left)
&& isSubtree(pRootA->right, pRootB->right);
} else return false;
}
public:
bool HasSubtree(TreeNode* pRootA, TreeNode* pRootB)
{
if (pRootA == NULL || pRootB == NULL) return false;
return isSubtree(pRootA, pRootB) || HasSubtree(pRootA->left, pRootB) || HasSubtree(pRootA->right, pRootB);
}
};