N皇后//搜索入门

 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 #include<algorithm>
 5 using namespace std;
 6 int n;
 7 int a[15];//×ÝÁÐ 
 8 int b[30];//ÐмÓÁеĽá¹ûÖµ 
 9 int c[30];//ÐмõÁеĽá¹ûÖµ 
10 int rec[15];//¼Ç¼×ÝÁеÄÁÐÊý 
11 int ans=0;
12 void dfs(int num)//hang
13 {
14     for(int i=1;i<=n;i++)
15     {
16         if(a[i]==0&&b[i+num]==0&&c[num-i+14]==0)
17         {
18             rec[num]=i;
19             if(n==num)
20             {
21                 ans++;
22                 if(ans<=3)
23                 {
24                     for(int j=1;j<=n;j++) printf("%d ",rec[j]);
25                     puts("");
26                 }
27                 continue;
28             }
29             a[i]=b[i+num]=c[num-i+14]=1;
30             dfs(num+1);
31             a[i]=b[i+num]=c[num-i+14]=0;
32         }
33     }
34 }
35 int main()
36 {    
37     cin>>n;
38     dfs(1);
39     cout<<ans;
40     puts("");
41     return 0;
42 }