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#include <bits/stdc++.h> 
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 = 10; 
    cout << "Sum of series of power of 2 is : "
         << calculateSum(n); 
} 



and ı wanted Scanf for N .
(1<<i) what="" that="" mean="" ?="" <<

<b="">What I have tried:

ı dont know C++ coding so
ı know c programming

What I have tried:

ı dont know C++ coding so
ı know c programming
Posted
Updated 20-Jan-21 23:35pm
v2

It is not clear if you need the C or the C++ version of the code.
  • 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";
}



Notes
  • The sum can quicky overflow the variables

  • The function can be rewritten, more concisely, this way:
    int calculateSum(int n)
    {
      return ( (1 << n) - 1);
    }

   
All C code works in C++. But you should learn the C++ way to do things in time.

This is valid C++.
   

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)




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