insane.cpp

insane.cpp

int bt(int pos, int cur, int used)
{
    if (pos == n)
        return used == 7 ? 0 : 150000 * 5;
    if (cur != -1 && D[pos][used][cur] != 0)
        return D[pos][used][cur];

    int bs = 5 * 150000;
    for (int i = 0; i < 3; ++i)
        if (!(used & 1 << i) || i == cur)
            bs = min(bs, A[i][pos] + bt(pos + 1, i, used | 1 << i));
    return cur != -1 ? D[pos][used][cur] = bs : bs;
}