POJ 1674

 1 #include<iostream>//cheng da cai zi 08 .11 .13
 2 using namespace std;
 3 int main()
 4 {
 5     int digit_num;
 6     int result=0;
 7     int i;
 8     int time;
 9     cin>>time;
10     while(time--){
11     result=0;
12     cin>>digit_num;
13     bool * already=new bool[digit_num+1];
14     for(i=1;i<=digit_num;i++)
15         already[i]=false;
16     int * digit=new int[digit_num+1];
17     for(i=1;i<=digit_num;i++)
18         cin>>digit[i];
19     for(i=1;i<=digit_num;i++)
20     {
21         while(already[i]==false)
22         {
23             if(digit[i]==i)
24                 already[i]=true;
25             else
26             {
27                 already[digit[i]]=true;
28                 result++;
29                 digit[i]=digit[digit[i]];
30             }
31         }
32 
33     }
34     cout<<result<<endl;
35     delete []already;
36         delete []digit;
37     }
38     return 0;
39 }