[easy] number permutation challenge solution

/*
 * Challenge from: https://www.youtube.com/watch?v=2bkfA2fHVwg
 *
 * "Write a program to display all valid department number permutations"
 *
 * Department numbers
 *
 * Fire
 * Police
 * Sanitation
 *
 * police# must be even
 * each in range 1 - 7
 * must be unique
 * must add up to 12
 */

#include <stdio.h>

enum { d_fir, d_pol, d_san };

int
incr(int *nums)
{
    int isbrk = 0;

    for(int i = 2; i >= 0; nums[i] = 1, i--)
        if(++nums[i] <= 7 && (isbrk = 1))
            break;

    return isbrk;
}

int
check(int *nums)
{
    return nums[d_pol] % 2 == 0
        && nums[0] + nums[1] + nums[2] == 12
        && nums[0] != nums[1]
        && nums[0] != nums[2];
}

int
main(void)
{
    int nums[3] = {1,1,0};

    while(incr(nums))
        if(check(nums))
            printf("Fire#%i Police#%i Sanitation #%i\n",
                    nums[d_fir], nums[d_pol], nums[d_san]);

    return 0;
}