void newboard ( int A[9][9], int S[9][9] )
{
   int P[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }, *Q, i, j, k, r, s, t;

   int B[9][9] = { {1, 0, 0, 0, 0, 8, 0, 0, 9},
                   {0, 0, 2, 0, 0, 0, 0, 0, 8},
                   {0, 8, 0, 5, 4, 9, 0, 0, 0},
                   {0, 4, 0, 2, 0, 0, 9, 0, 0},
                   {3, 0, 9, 0, 0, 0, 2, 0, 1},
                   {0, 0, 1, 0, 0, 5, 0, 4, 0},
                   {0, 0, 0, 9, 1, 2, 0, 3, 0},
                   {7, 0, 0, 0, 0, 0, 1, 0, 0},
                   {2, 0, 0, 7, 0, 0, 0, 0, 6}
                 },
       C[9][9] = { {1, 3, 4, 6, 2, 8, 5, 7, 9},
                   {9, 5, 2, 1, 3, 7, 4, 6, 8},
                   {6, 8, 7, 5, 4, 9, 3, 1, 2},
                   {5, 4, 6, 2, 7, 1, 9, 8, 3},
                   {3, 7, 9, 4, 8, 6, 2, 5, 1},
                   {8, 2, 1, 3, 9, 5, 6, 4, 7},
                   {4, 6, 8, 9, 1, 2, 7, 3, 5},
                   {7, 9, 5, 8, 6, 3, 1, 2, 4},
                   {2, 1, 3, 7, 5, 4, 8, 9, 6}
                 };

   srand((unsigned int)time(NULL));
   Q = P + 1;
   for (i=8; i>0; --i) {
      j = rand() % (i + 1);
      t = Q[i]; Q[i] = Q[j]; Q[j] = t;
   }
   for (k=0; k<9; k+=3) {
      s = rand() % 3;
      t = rand() % 3;
      if (s != t) {
         for (j=0; j<9; ++j) {
            r = B[k+s][j]; B[k+s][j] = B[k+t][j]; B[k+t][j] = r;
            r = C[k+s][j]; C[k+s][j] = C[k+t][j]; C[k+t][j] = r;
         }
      }
   }
   for (k=0; k<9; k+=3) {
      s = rand() % 3;
      t = rand() % 3;
      if (s != t) {
         for (i=0; i<9; ++i) {
            r = B[i][k+s]; B[i][k+s] = B[i][k+t]; B[i][k+t] = r;
            r = C[i][k+s]; C[i][k+s] = C[i][k+t]; C[i][k+t] = r;
         }
      }
   }
   if (rand()%2) {
      for (i=0; i<9; ++i) {
         for (j=0; j<9; ++j) {
            A[i][j] = P[B[i][j]];
            S[i][j] = P[C[i][j]];
         }
      }
   } else {
      for (i=0; i<9; ++i) {
         for (j=0; j<9; ++j) {
            A[i][j] = P[B[j][i]];
            S[i][j] = P[C[j][i]];
         }
      }
   }
}