N Queen Problem using c and c++

N Queen Problem using c and c++

Here you will get a program for N queens problem in C using backtracking.

N Queens Problem is a famous puzzle in which n-queens are to be placed on a nxn chessboard such that no two queens are in the same row, column or diagonal. In this tutorial, I am sharing the C program to find a solution for N Queens problem using backtracking. Below animation shows the solution for 8 queens problem using backtracking.

#include<stdio.h>

#include<conio.h>

#include<math.h>

int x[100];

void main()

{

                clrscr();

                void n_queen(int,int);

                int n;

                printf("\n\t Enter Queen Value : ");

                scanf("%d",&n);

                n_queen(1,n);

                getch();

}

void n_queen(int k,int n)

{

                int p(int ,int);

                for(int i=1;i<=n;i++)

                {

                                if(p(k,i))

                                {

                                                x[k]=i;

                                                if(k==n)

                                                {

                                                                printf("\n");

                                                                for(int j=1;j<=n;j++)

                                                                                printf("\t %d",x[j]);

                                                                printf("\n");

                                                                getch();

                                                                return;

                                                }

                                                else

                                                                n_queen(k+1,n);

                                }

                }

}

int p(int k,int i)

{

                for(int j=1;j<k;j++)

                                if((x[j]==i) || (abs(x[j]-i)== abs(j-k)))

                                                return 0;

                                                return 1;

}