C语言解决8皇后问题

C语言解决8皇后问题

#include<iostream>
using std::cout;
using std::endl;
#define my_abs(x) ((x)>=0?(x):(-(x)))
const int n=8;
void output(int a[],int n)
{
static int count=1;
cout<<"this is the "<<count<<"th answer"<<endl<<endl;
for (int i=1;i<=n;i++)
cout<<i<<" "<<a[i]<<endl;
count++;
}
bool constraint(int a[],int k)
{
for(int i=1;i<k;i++)
	if(my_abs(k-i)==my_abs(a[k]-a[i])||(a[i]==a[k]))
	return false;
return true;
}
void back_track(int a[],int i)
{
if(i>n)
{
output(a,n);
}
else
{
for(int j=1;j<=n;j++)
	{
	a[i]=j;
	if(constraint(a,i))
		back_track(a,i+1);
	}
}
}
int main()
{
int *a=new int[n+1];
back_track(a,1);
delete []a;
return 0;
}