CLOCKSYNC-WA.cc

#include <stdio.h>
#include <algorithm>

#define swc(i) (1L << (i * 3))
long long switches[10] = {
    swc(0) | swc(1)  | swc(2),
    swc(3) | swc(7)  | swc(9)  | swc(11),
    swc(4) | swc(10) | swc(14) | swc(15),
    swc(0) | swc(4)  | swc(5)  | swc(6)  | swc(7),
    swc(6) | swc(7)  | swc(8)  | swc(10) | swc(12),
    swc(0) | swc(2)  | swc(14) | swc(15),
    swc(3) | swc(14) | swc(15),
    swc(4) | swc(5)  | swc(7)  | swc(14) | swc(15),
    swc(1) | swc(2)  | swc(3)  | swc(4)  | swc(5),
    swc(3) | swc(4)  | swc(5)  | swc(9)  | swc(13),
};
long long mask = 0x6db6db6db6dbL;
int MAX = 987654321;

int solve(long long clocks, int s)
{
    if (s < 0)
        return clocks == 0 ? 0 : MAX;

    int result = MAX;
    for (int i = 0; i < 4; i++) {
        result = std::min(result, i + solve(clocks, s-1));
        clocks = (clocks + switches[s]) & mask;
    }
    return result;
}

int main()
{
    int c;
    int i;
    int x;
    int ignore;
    long long clocks;

    ignore = scanf("%d\n", &c);
    while (c--) {
        clocks = 0L;
        for (i = 0; i < 16; i++) {
            ignore = scanf("%d", &x);
            clocks |= (long long) ((x / 3) % 4) << (i*3);
        }
        x = solve(clocks, 9);
        printf("%d\n", x < MAX ? x : -1);
    }

    return 0;
}