Using a while loop to calculate the sum of integers from 1 to n and n! - C++ Statement

C++ examples for Statement:while

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Description

Using a while loop to calculate the sum of integers from 1 to n and n!

Demo Code

#include <iostream>
#include <iomanip>

int main()//  w ww .j  a  v  a 2 s  . c o m
{
  unsigned int limit {};
  std::cout << "This program calculates n! and the sum of the integers"
    << " up to n for values 1 to limit.\n";
  std::cout << "What upper limit for n would you like? ";
  std::cin >> limit;

  // Output column headings
  std::cout << std::setw(8) << "integer" << std::setw(8) << " sum"
            << std::setw(20) << " factorial" << std::endl;
  unsigned int n {};
  unsigned int sum {};
  unsigned long long factorial {1ULL};

  while (++n <= limit)
  {
    sum += n;                          // Accumulate sum to current n
    factorial *= n;                    // Calculate n! for current n
    std::cout << std::setw(8) << n << std::setw(8) << sum
              << std::setw(20) << factorial << std::endl;
  }
}

Result


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