private int guess() {
for (int i = s; i > 0; i--) {
for (int j = 0; j < s; j++) {
for (int k = 0; k < s; k++) {
if (!grid.cellFilled(j, k) && grid.possible(j, k, i)) {
grids.push(grid.clone());
guesses.push(new int[] {j, k, i});
// System.out.println("guessing row: "+j+" col: "+k+" is "+i );
// System.out.println(grids.size() + "");
int r = grid.setCellVal(j, k, i);
// System.out.println(grid);
if (r == 1) {
System.out.println("solved");
return 1;
} else if (r == -1) {
while (r == -1) {
if (grids.isEmpty()) {
System.out.println("unsolvable");
return -1;
}
int[] lastGuess = guesses.pop();
// System.out.println("bad guess, removing
// possibility of row: " + lastGuess[0] + " col: " + lastGuess[1] + " being " +
// lastGuess[2]);
// System.out.println(grid);
grid = grids.pop();
// System.out.println(grids.size() + "");
r = grid.setCellNot(lastGuess[0], lastGuess[1], lastGuess[2]);
}
return r;
} else {
System.out.println("not enough info");
return 0;
}
}
}
}
}
return -1;
}
