Build Binary Search Tree

 /* LeetCode 536. Construct Binary Tree from String* * You need to construct a binary tree from a string consisting of parenthesis and integers.* * The whole input represents a binary tree. It contains an integer followed by zero, one or two pairs of parenthesis. The integer represents the root's value and a pair of parenthesis contains a child binary tree with the same structure.* * You always start to construct the left child node of the parent first if it exists.* * Example:* * Input: "4(2(3)(1))(6(5))"* Output: return the tree root node representing the following tree:*        * 4     * /   \    * 2     6   * / \   /   * 3   1 5   */#include <iostream>#include <list>#include <unordered_set>#include <vector>#include <algorithm>#include <algorithm>#include <random>#include <functional>#include <string>#include <memory>#include <stdexcept>      // std::out_of_range#include <stack>using namespace std;template <typename T>class binaryNode {public:    /* default ctor */    binaryNode(): key(0), left(nullptr), right(nullptr), p(nullptr) {}    /* ctor  */    binaryNode(const binaryNode &n):         key(n.key), left(n.left), right(n.right),p(n.p) {}    binaryNode(const T& t):key(t), left(nullptr), right(nullptr), p(nullptr){}    /* dtor */    ~binaryNode() = default;/* data member */public:    binaryNode *left;    binaryNode *right;    binaryNode *p;    T key;};vector<shared_ptr<binaryNode<int>>> vshes;vector<binaryNode<int>*> vptrs;char ms[100000];void buildTree(char *b, char *e, binaryNode<int>* root) {   char *it = b;   string mk;   for (;it != e; ++it) {       if (*it != '(')            mk += *it;       else break;   }   int key = stoi(mk);   if (!root) {       cerr << "Wriong: root is nil\n";       return;   }   root->key = key;   if (it != e) {/*one child exist at least*/       string s1;       it++;       int num_l = 1;       char *b1 = it, *b2, *e2;       for (;it != e; ++it) {           if (*it == '(')               num_l++;           else if (*it == ')') {               num_l--;               if (num_l == 0) {                   break;               }           }       }       static int m11 = 0;m11++;       shared_ptr<binaryNode<int>> c0sh = make_shared<binaryNode<int>>(binaryNode<int>(0));       vshes.push_back(c0sh);       shared_ptr<binaryNode<int>> c1sh = nullptr;       char *e1 = it;       c0sh->p = root;       it++;       if (it != e) {/* two */           it++;           b2 = it;           e2 = e-1;           c1sh = make_shared<binaryNode<int>> (binaryNode<int>(0));           vshes.push_back(c1sh);       }       buildTree(b1,e1,c0sh.get());       c0sh->p = root;       //try { ///////////////       if (c1sh) {           c1sh->p = root;           buildTree(b2,e2,c1sh.get());           root->right = c1sh.get();           root->left = c0sh.get();       }       else {           root->left = c0sh.get();           root->right = nullptr;       }   }    else { /* none child exists */       return;   }   return;}void printTree(binaryNode<int> *t) {    if (t) {        cout << t->key << " ";        printTree(t->left);        printTree(t->right);    } else return;}int main() {   string mstr;   cin >> mstr;   copy(mstr.begin(), mstr.end(), ms);   ms[mstr.size()] = '\0';   auto p1 = make_shared<binaryNode<int>>(binaryNode<int>(0));   binaryNode<int>* root = p1.get();   buildTree(ms, ms+mstr.size(),root);   printTree(root);   return 0;}