#include using namespace std; 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: priority_queue, greater > vals; int cnt = 0; void traverse(TreeNode * node){ vals.push(node->val); cnt++; if(node->left!=nullptr) traverse(node->left); if(node->right!=nullptr) traverse(node->right); } TreeNode* bstToGst(TreeNode* root) { traverse(root); int val[110]; int idx[110]; int pref[110],sum=0; for(int i = 0 ; i < cnt ; i++){ val[i] = vals.top(); vals.pop(); if(i==0) pref[i] = val[i]; else{ pref[i] = pref[i-1] + val[i]; } } sum = pref[cnt-1]; for(int i = 0 ; i < cnt ; i++){ idx[val[i]] = sum - pref[i]; } stack sta; sta.push(root); while(sta.empty() == false){ TreeNode* top_node = sta.top(); cout<<"top_node is "<val<left!=nullptr) sta.push(top_node->left); if(top_node->right!=nullptr) sta.push(top_node->right); top_node->val+=idx[top_node->val]; } cnt = 0; std::priority_queue, std::greater> empty; vals.swap(empty); return root; } }; void create(int * val, int cnt, TreeNode *cur,int idx){ int left_idx = (idx + 1) * 2 - 1; int right_idx = (idx + 1) * 2 ; if(left_idx > cnt){ cur->left = nullptr; cur->right = nullptr; return; } if(right_idx > cnt){ cur->right = nullptr; return; } if(val[left_idx] == -1){ cur -> left = nullptr; }else{ TreeNode * left_child = new TreeNode(val[left_idx]); cur->left = left_child; create(val,cnt,left_child,left_idx); } if(val[right_idx] == -1){ cur -> right = nullptr; }else{ TreeNode * right_child = new TreeNode(val[right_idx]); cur->right = right_child; create(val, cnt, right_child, right_idx); } return; } void traverse(TreeNode* node){ cout<val<<' '; if(node->left != nullptr){ traverse(node->left); } if(node->right != nullptr){ traverse(node->right); } return; } TreeNode* createTree(int * val, int cnt){ TreeNode * root = new TreeNode(val[0]); cout<<"create a tree"<