N皇后2(算法)

set cols[N] pie[N] i + j na[N] i - j

int col, pie, na;

伪代码 void DFS(row, col, pie, na) if (row >= N) { count++; return; } bits = (~(col | pie | na)) & ((1 << n) - 1) while (bits > 0) { P = bits & - bits DFS(row + 1, col | P(pie | P) << 1, (na | P) >> 1) bits &= bits - 1 }