java:implement 8 queen using depth first search

Question

i am try to implement 8 queen using depth search for any initial state it work fine for empty board(no queen on the board) ,but i need it to work for initial state if there

Answer 1

Try to alter your method IsValid in the lines where for (x = 0; x < board.length - 1; x++).

public static boolean IsValid(int[][] board, int i, int j) {
    int x;
    //check the queens in column
    for (x = 0; x < board.length - 1; x++) {
        if (board[i][x] != 0) {
            return false;
        }
    }
    //check the queens in row
    for (x = 0; x < board.length - 1; x++) {
        if (board[x][j] != 0) {
            return false;
        }
    }
    //check the queens in the diagonals
    if (!SafeDiag(board, i, j)) {
        return false;
    }
    return true;
}