C++ Logic Error (boolean) -

template <class t> bool bst<t>::printsubtree(t item) {   int id;   bool result;   if (root==null)   {     cout << "empty tree, please insert data" << endl;     return false;   }  cout << "enter id print sub-tree" << endl; cin >> id; result=searchsubtree(id, item);   if(result == false)  {      cout << "record not found" << endl << endl;  } //preorderprint(); return true;   }  template <class t> bool bst<t>::searchsubtree(int target, t &item) {  btnode<t> *cur, *curtemp; bool flag = false; if (root==null) {     cout << "empty tree, please insert data" << endl;     return false; } cur = root; curtemp = root;  while(!flag && cur!= null) {     if(curtemp->item.id == target)     {         flag = true;         root = curtemp; //promote desired node become root temporarily         inorderprint();         flag = true;     }      else if (curtemp->item.id < target) //target value greater current value, search right sub-tree     {         curtemp = curtemp->right;     }      else if (curtemp->item.id > target) //search left sub-tree     {         curtemp = curtemp -> left;     }        root = cur; //set root position ori place }  return flag;   } 

in code above, running fine. however, why tried input value doesn't exist(id input) , program crash, can't proceed if(result == false). may know what's problem on here?

thanks guides!

your while statement shall use curtemp instead of cur.

while(!flag && curtemp!= null)