EIGHT QUEEN’S PROBLEM

#include<stdio.h>

#include<conio.h>

#define QUEENNO 8

void placequeen(int, int*);

int canbeplaced(int, int, int*);

void showboard(int*);

void main()

{

int x[QUEENNO], i;

clrscr();

printf("The 8 queens problem");

placequeen(0, x);

printf("End");

getch();

}

void placequeen(int k, int *x)

{

int i, j;

char ch;

for(i = 0; i < 8; i++)

{

if(canbeplaced(k, i, x))

{

x[k] = i;

if(k == 7)

{

showboard(x);

printf(" Want to see more?[n->stop, any-> continue]: ");

scanf(" %c ", &ch);

if(ch == 'n' || ch == 'N')

exit(0);

}

if(k < 7)

placequeen(k + 1, x);

}

}

}

int canbeplaced(int k, int i, int *x)

{

int j;

for(j = 0; j < k; j++)

{

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

return 0;

}

return 1;

}

void showboard(int *x)

{

int i, j;

printf(" \n----------------------------------------------\n ");

printf(" ");

for(i = 0; i < 8; i++)

{

printf(" %d ",(i + 1));

printf(" ");

}

for(i = 0; I < 8; i++)

{

printf(" \n \n %d ",(i + 1));

for(j = 0; j < 8; j++)

{

if(j == x[i])

printf(" Q ");

else

printf(" - ");

printf(" ");

}

printf(" ");

}

printf(" \n---------------------------------------------- ");

}

Output:

The 8 Queens’ Problem

------------------

1 2 3 4 5 6 7 8

1 Q - - - - - - -

2 - - Q - - - - -

3 - - - - Q - - -

4 - - - - - - Q -

5 – Q - - - - - -

6 - - - Q - - - -

7 - - - - - Q - -

8 - - - - - - - Q

------------------ Want to see more?[n->stop, any-> continue]: N