1 #include 
      
        2 #include 
       
         3 #include 
        
          4 using namespace std; 5  6 int main() 7 { 8     int i,j,k,T; 9     int n;10     char str[10]={
    '1','2','3','4','5','6','7','8','9'};//实际上可以吧10省略 11     cin>>T;12     while(T--)13     {14         cin>>n;15         k=0;16         do 17         {18             for(i=0;i
        
       
      

1 #include 
     
        2 #include 
      
        3 #define MAX 10  4 bool vis[MAX];  5 int res[MAX];  6 int N;  7 void output() 8 {  9     int i; 10     for(i = 0; i < N; i++) 11         printf("%d", res[i]); 12     printf("\n"); 13 } 14 void dfs(int step)15 { 16     int i; 17     if(step == N) 18         output(); 19     else20     { 21         for(i = 0; i < N; i++)22         { 23             if(!vis[i])24             { 25                 vis[i] = 1; 26                 res[step] = i + 1; 27                 dfs(step + 1); 28                 vis[i] = 0; 29             } 30         } 31     } 32 } 33 34 int main()35 { 36     int t;37     scanf("%d",&t);38     while(t--)39     {40           memset(vis,0,sizeof(vis));41         scanf("%d", &N); 42         dfs(0); 43     }44     return 0;45 } 46 47