Tim Varley Tim Varley

Euler 001 c++ Solution

Multiples of 3 and 5
Dec 30, 2014
3 minute read

Problem

https://projecteuler.net/problem=1

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.

Answer: 233168

Solution

euler001.cpp

#include <iostream>
int sum_natural_35(size_t upper)
{
  unsigned int sum(0);
  for( int i = upper ; --i; )
  {
    if( 0 == i % 3 )
    {
      sum += i;
    }
    else if ( 0 == i % 5 )
    {
      sum += i;
    }
  }
  return sum;
}

int main(int argc, char* argv[])
{
  std::cout << sum_natural_35(1000) << std::endl;
}

See Also

# cpp go java php ruby rust javascript
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# cpp ruby
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