Misc-small-projects/isPrime.c
Daniel Løvbrøtte Olsen 866bd5756f Added isPrime.c
Checks if a number (n) is a prime, also lists all it's factors
2015-08-27 21:19:24 +02:00

32 lines
599 B
C

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char* argv[])
{
if (argc != 2)
{
printf("Usage = ./isPrime <n>");
return -1;
}
int n = atoi(argv[1]);
int results = 0;
for (int i = 1; i < n + 1; i++)
{
if (n % i == 0)
{
printf("%i is divisible by %i\n", n, i);
results++;
}
}
if (results == 2)
{
printf("%i is a prime.\n", n);
}
else
{
printf("%i is not a prime, as it's divisible by %i numbers other than 1 and %i\n", n, results - 2, n);
}
}