八皇后

传送门：https://www.luogu.org/problemnew/show/P1219

代码

#include<cstdio>
using namespace std;
int n;
int a[100],b[100],c[100],d[100],tot;
int print(){
    tot++;
    if(tot <= 3){
        for(int i = 1;i <= n;i++) printf("%d ",a[i]);
    printf("
");
    }
}
void search(int i)//第几行 
{
    if(i > n){
        print();
        return;
    }
    else{
        for(int j = 1;j <= n;j++){
            if(!b[j] && !c[i+j] && !d[i-j+n]){
                a[i] = j;
                b[j] = c[i+j] = d[i-j+n] = true;
                search(i+1);
                b[j] = c[i+j] = d[i-j+n] = false;
            }
        }
    }
}
int main()
{
    scanf("%d",&n);
    search(1);
    printf("%d",tot);
    return 0;
}