ProjectEuler/src/main.c

#include <stdio.h>
#include "utils.h"

/*
The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...

Let us list the factors of the first seven triangle numbers:

 1: 1
 3: 1,3
 6: 1,2,3,6
10: 1,2,5,10
15: 1,3,5,15
21: 1,3,7,21
28: 1,2,4,7,14,28
We can see that 28 is the first triangle number to have over five divisors.

What is the value of the first triangle number to have over five hundred divisors?

https://projecteuler.net/problem=12
*/

int main(int argc,char**argv) {
    int counter=1;
    long sum=0;
    while (true) {
        sum+=counter;
        printf("Checking %ld...\n",sum);
        int current=1;
        int max=sum;
        int divisorCount=0;
        while (current<max) {
            if (max==current&&sum%current==0) {
                divisorCount++;
                break;
            } else
            if (sum%current==0) {
                max=sum/current;
                divisorCount+=2;
            }
            current++;
        }
        printf(" has %d divisors.\n",divisorCount);
        if (divisorCount>500) {
            printf("\n\nNumber %ld has %d divisors!",sum,divisorCount);
            return 0;
        }
        counter++;
    }
    return 0;
}