int put_queen_brute(int nb_queen, char board[8][8], int possibility, solution **s, options *op) {
int posy = 0;
int posx = 0;
for (; posy < 8; ++posy) {
for (posx = 0; posx < 8; ++posx) {
if (!board[posy][posx]) {
set_queen(nb_queen, board, posx, posy);
if (nb_queen == 8) {
if (add_solution(board, s)) {
possibility += 1;
print_board(board, possibility, op);
if (possibility == 92 && op->stop_before_end)
op->end = 1;
}
}
else
possibility = put_queen_brute(nb_queen + 1, board, possibility, s, op);
unset_queen(nb_queen, board);
if (op->end)
return possibility;
}
}
}
return possibility;
}
/*
* make the next solve move
*/
int solve_next_move()
{
int moved = 0;
int on;
// done - found solution
if(queen == SOLVE_NQUEENS)
{
sprintf(move_buff[(move_count++)%MOVE_WRAP], "Complete!!!");
return 1;
}
// done - did not find solution
if(queen < 0)
{
sprintf(move_buff[(move_count++)%MOVE_WRAP], "Failed.");
return -1;
}
// should only run once or twice
while(!moved)
{
on = queen_on(queen);
moved = 1;
// from last time
if(on)
{
remove_queen(queen);
}
// add to board
else
{
stack[queen].di = rand()%SOLVE_SIZE;
stack[queen].dj = rand()%SOLVE_SIZE;
stack[queen].i = 0;
}
// find open spot
do
{
// increment position
++stack[queen].j;
if(stack[queen].j == SOLVE_SIZE){
stack[queen].j = 0;
++stack[queen].i;
// exhausted - backtrack
if(stack[queen].i == SOLVE_SIZE)
{
stack[queen].i = stack[queen].j = -1;
--queen;
if(on){
mn = 0;
sprintf(move_buff[(move_count++)%MOVE_WRAP],
"...Exhausted spaces for Queen %d.", queen+2);
return 0;
}
mn = 1;
sprintf(move_buff[(move_count++)%MOVE_WRAP],
"...No place for Queen %d.", queen+2);
moved = 0;
break;
}
}
} while(!solve_spot_open(Si(queen), Sj(queen)));
}
mn = 0;
sprintf(move_buff[(move_count++)%MOVE_WRAP],
"Move Queen %d to %c%d.", queen+1, Si(queen)+'A', Sj(queen)+1);
// place queen
set_queen(queen);
// get next queen
++queen;
return 0;
}
