int n_queen(int n)
{
for (;;) {
if(board[0] == SIZE){
return 0;
}
else if(n == SIZE){
count++;
board[SIZE - 1] = 0;
board[SIZE - 2]++;
n = SIZE - 2;
}
else if(board[n] == SIZE){
board[n] = 0;
board[n - 1]++;
n = n - 1;
}
else if(effect(n)){
n = n + 1;
}
else{
board[n]++;
}
}
}