八皇后算法

#include "stdafx.h"

#include<stdio.h>

#define NUM 8

int a[NUM+1];

void main()

{

       int i,k,flag,not_finish=1,count=0;

       i=1;

       a[1]=1;

       printf("The possible configuration of 8 queens are:/n");

while(not_finish)

{

    while(not_finish&&i<=NUM)

     {

         for(flag=1,k=1;flag&&k<i;k++)

             if(a[k]==a[i])

     flag=0;

           for(k=1;flag&&k<i;k++)

              if((a[i]==a[k]-(k-i))||(a[i]==a[k]+(k-i)))

      flag=0;

               if(!flag)

                  {

       if(a[i]==a[i-1])

       {

        i--;

        if(i>1&&a[i]==NUM)

         a[i]=1;

        else if(i==1&&a[i]==NUM)

         not_finish=0;

        else a[i]++;

       }

       else if(a[i]==NUM) a[i]=1;

       else a[i]++;

      }

      else if(++i<=NUM)

       if(a[i-1]==NUM) a[i]=1;

       else a[i]=a[i-1]+1;

  }

  if(not_finish)

  {

   ++count;

   printf((count-1)%3?" [%2d]: ":" /n[%2d]: ",count);

   for(k=1;k<=NUM;k++)

    printf(" %d",a[k]);

   if(a[NUM-1]<NUM) a[NUM-1]++;

   else a[NUM-1]=1;

   i=NUM-1;

  }

}

printf("/n");

}