Subtree of Another Tree
给一个树, 求另外一个树是不是这个树的子树.
先写一个方法判断isSameTree, 然后遍历即可.
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/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode() : val(0), left(nullptr), right(nullptr) {} * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} * TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {} * }; */ class Solution { public: bool isSubtree(TreeNode* s, TreeNode* t) { if(!s) return false; if(isSametree(s, t)) return true; return isSubtree(s->left, t) || isSubtree(s->right, t); } bool isSametree(TreeNode* s, TreeNode* t) { if (!s && !t) return true; if(!s || !t) return false; if (s->val != t->val) return false; return isSametree(s->left, t->left) && isSametree(s->right, t->right); } }; |