algorithms/nQueens at master · SravanthiAshokKumar/algorithms · GitHub

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import java.util.*;
public class nQueens
{
	int board[][],order;
	int col[];
	int inf=9999;
	nQueens(int n)
	{
		order=n;
		board=new int[order][order];
		col=new int[order];
		for(int i=0;i<order;i++)
		{
			for(int j=0;j<order;j++)
				board[i][j]=9999;
			col[i]=inf;
		}
	}
	void placeQueens(int k)
	{
		for(int i=0;i<order;i++)
		{
			if(bound(i,k))
			{
				col[k]=i;
				if(k==order-1)
                		{
		                    printBoard();
                		}
				else
					placeQueens(k+1);

			}
		}
	}
	boolean bound(int i,int k)
	{
		for(int j=0;j<k;j++)
			if((abs(j,k)==abs(col[j],i))||(col[j]==i))
				return false;
		return true;
	}
	void printBoard()
	{
		for(int i=0;i<order;i++)
			for(int j=0;j<order;j++)
				board[i][j]=inf;
		for(int i=0;i<order;i++)
			board[i][col[i]]=i;
		for(int i=0;i<order;i++)
		{
			for(int j=0;j<order;j++)
			{
				if(board[i][j]==inf)
					System.out.print("--\t");
				else
					System.out.print(board[i][j]+"\t");
			}
			System.out.println("\n\n");
		}
		System.out.print("*****************************\n");
	}
	int abs(int a,int b)
	{
		int k=a-b;
		return (k<0)?(b-a):(a-b);
	}
	public static void main(String args[])
	{
		nQueens q=new nQueens(5);
		q.placeQueens(0);
//		q.printBoard();
	}
}