How do write that C++ programming code on C programming )

• C version

#include <stdio.h>
  
int calculateSum(int n)
{
  int sum = 0;
  for (int i = 0; i < n; i++)
  {
    // calculate 2^i 
    sum = sum + (1 << i);
  }
  return sum;
}

int main()
{
  int n;
  printf("please enter N\n");
  if ( scanf("%d",&n ) == 1)
    printf("Sum of series of power of 2 is : %d\n", calculateSum(n));
}

• C++ version

#include <iostream>
using namespace std;

int calculateSum(int n)
{
  int sum = 0;
  for (int i = 0; i < n; i++)
  {
    // calculate 2^i 
    sum = sum + (1 << i);
  }
  return sum;
}

int main()
{
  int n;
  cout << "please enter N\n";
  cin >> n;
  cout << "Sum of series of power of 2 is : " << calculateSum(n) << "\n";
}

• The sum can quicky overflow the variables

• The function can be rewritten, more concisely, this way:
  
  C++

  int calculateSum(int n)
  {
    return ( (1 << n) - 1);
  }