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