CTCI 9.9

Write an alogrithm to print all ways of arranging eight queens on an 8*8 chess board so that none of them share the same row, colum or diagonal. In this case, "diagonal" means all diagonals, not just the two that bisect the board.

CTCI 9.9.java

public static ArrayList<int[]> Queues(){
    ArrayList<int[]> ways = new ArrayList<>();
    int[] colums = new int[COLUMSIZE];
    queues(0, colums, ways);
    return ways;
}

public static void queues(int colum, int[] colums, ArrayList<int[]> ways){
    if(colum == COLUMSIZE) ways.add(colums.clone);
    for(int i = 0; i < ROWSIZE; i++){
        if(check(colum, i, colums){
            colums[colum] = i;
            queues(colum + 1, colums, ways);
        }
    }
}
public static boolean check(int colum, int value, int[] colums){
    for(int i = 0; i < colum; i++){
        if(colums[i] == value) return false;
        if(Math.abs(colums[i] - value) == colum - i) return false;
    }
    return true;
}