| if (M >= 0 && N >= 0) | |
| for (int c0 = -4; c0 <= 3 * M + N; c0 += 1) { | |
| if (c0 >= 3 * M) { | |
| S2(M, -3 * M + c0); | |
| } else if (3 * M >= c0 + 4 && (c0 + 1) % 3 == 0) { | |
| S1((c0 + 4) / 3, 0); | |
| } | |
| for (int c1 = max(-3 * M + c0 + 3, (c0 + 6) % 3); c1 <= min(N - 1, c0); c1 += 3) { | |
| S2((c0 - c1) / 3, c1); | |
| S1(((c0 - c1) / 3) + 1, c1 + 1); | |
| } | |
| if (3 * M + N >= c0 + 3 && c0 >= N && (N - c0) % 3 == 0) { | |
| S2((-N + c0) / 3, N); | |
| } else if (N >= c0 + 4 && c0 >= -3) { | |
| S1(0, c0 + 4); | |
| } | |
| for (int c1 = max(-3 * M + c0, (c0 + 6) % 3); c1 <= min(N, c0); c1 += 3) | |
| S3((c0 - c1) / 3, c1); | |
| } |