sol3.c File Reference

Problem 1 solution. More...

#include <stdio.h>

Include dependency graph for sol3.c:

Functions
int	main ()
	Main function.

Detailed Description

Problem 1 solution.

This solution is based on the pattern that the successive numbers in the series follow: 0+3,+2,+1,+3,+1,+2,+3.

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 N.

Function Documentation

main()

int main

(

void

)

Main function.

{
    int n = 0;
    int sum = 0;
    int num = 0;
    scanf("%d", &n);
 
    while (1)
    {
        num += 3;
        if (num >= n)
            break;
        sum += num;
        num += 2;
        if (num >= n)
            break;
        sum += num;
        num += 1;
        if (num >= n)
            break;
        sum += num;
        num += 3;
        if (num >= n)
            break;
        sum += num;
        num += 1;
        if (num >= n)
            break;
        sum += num;
        num += 2;
        if (num >= n)
            break;
        sum += num;
        num += 3;
        if (num >= n)
            break;
        sum += num;
    }
 
    printf("%d\n", sum);
    return 0;
}