euler_problem_1.c

#include <stdio.h>

int euler_1(int n);

int main() {
  int n;
  scanf("Please enter a number here: %d",&n);
  printf("Here is your answer: %d\n",euler_1(n));
  return 0;
}

int euler_1(int n) {
  int result = 0;
  float x = n/3;
  float y = n/5;

  for(int i = 1; i < x; i++) {
    result += 3*i;
  }

  for (int i = 1; i < y; i++) {
    if (5*i % 3 != 0) {
      result += 5*i;
    }
  }

  return result;
}