DFS-全排列

 1 void dfs(int x)
 2 {
 3     if(x>n)
 4     {
 5         for(int i=1;i<=n;++i) cout<<a[i];
 6         cout<<endl;
 7         return;
 8     }
 9     for(int i=1;i<=n;++i)
10     {
11         if(!v[i])
12         {
13             a[x]=i;v[i]=1;
14             dfs(x+1);
15             v[i]=0;
16         }
17     }
18 }
19 int main()
20 {
21     scanf("%d",&n);
22     dfs(1);
23     return 0;
24 }