class Solution { public: TreeNode* rebuild(vector<int>& pre, int pre_left, int pre_right, vector<int>& vin, int vin_left, int vin_right) { if (pre_left > pre_right) return nullptr; TreeNode* root = new TreeNode(pre[pre_left]); for (int i=vin_left; i<=vin_right; ++i) { if (vin[i] == root->val) { root->left = rebuild(pre, pre_left+1, pre_left+i-vin_left, vin, vin_left, i-1); root->right = rebuild(pre, pre_left+i-vin_left+1, pre_right, vin, i+1, vin_right); break; } } return root; } TreeNode* reConstructBinaryTree(vector<int> pre, vector<int> vin) { return rebuild(pre, 0, pre.size()-1, vin, 0, vin.size()-1); } };</int></int></int></int>