C++ making int array using new operation -

i want make dynamic array using new operator.

#include <iostream> using namespace std;  class set{    public:       set() { count = 0; }       set(int i) {          elements = new int;          elements[0] = i;          count = 1;       }       void add(int new_element) {          if(find(new_element) != -1) {             cout << "the set has " << new_element << " already.\n";             return;          }          else { //          elements[count] = new int;             elements[count++] = new_element;             cout << elements[count-1] << endl;          }       }       void remove(int remove_element) {          int index = find(remove_element);          if(index == -1) {             cout << "the set doesn't have " << remove_element << ".\n";             return;          }          else {             for(int i=index ; i<count ; i++)                elements[i] = elements[i+1];             count--;      }   }   void enumerate() {      for(int i=0 ; i<count ; i++)         cout << elements[i] << " ";      cout << endl;   }   ~set() {   }    private:       int* elements;       int count;       int find(int temp_element) {          int i=0;          for( ; i<count ; i++)             if(elements[i] == temp_element)                return i;          return -1;       } };  int main() {    set s1(1);    s1.add(2);    s1.add(3);    s1.remove(2);    s1.add(4);    s1.add(5);    s1.enumerate();    return 0; 

i know using stl makes problem easier. but, want know why code making error. and, don't know why works without line 18. @ last, how can free allocated storage? please, let me know answer.

you declared elements pointer int. meains elements[i] plain int. writing

elements[count] = new int; 

your attempting assign pointer newly allocated int it. it's not working because elements[count] int , not pointer.

as freeing allocated storage, std::vector keeps track how many elements contains lets use n. data[0] data[n-1] actual information. if had more storage @ end, leaves there without deallocating , trash value , doesn't let access it. can resize making new array new size, copying every element on old storage, calling delete[] on old pointer. watch out possible memory leaks though.