1 for (int c0 = 1; c0 <= M; c0 += 1) { 2 for (int c1 = 1; c1 <= min(M, c0 + 1); c1 += 1) 3 S1(c0, c1); 4 if (M >= c0 + 2) { 5 S1(c0, c0 + 2); 6 S2(c0, c0 + 2); 7 } 8 for (int c1 = c0 + 3; c1 <= M; c1 += 1) 9 S1(c0, c1); 10 if (c0 + 1 >= M) 11 S2(c0, c0 + 2); 12 } 13