Given any permutation of the numbers {0, 1, 2,…, N−1}, it is easy to sort them in increasing order. But what if Swap(0, *) is the ONLY operation that is allowed to use? For example, to sort {4, 0, 2, 1, 3} we may apply the swap operations in the following way:
Swap(0, 1) => {4, 1, 2, 0, 3}
Swap(0, 3) => {4, 1, 2, 3, 0}
Swap(0, 4) => {0, 1, 2, 3, 4}
Now you are asked to find the minimum number of swaps need to sort the given permutation of the first N nonnegative integers.

Input Specification:

Each input file contains one test case, which gives a positive N (≤10 ^5 ) followed by a permutation sequence of {0, 1, …, N−1}. All the numbers in a line are separated by a space.

Output Specification:

For each case, simply print in a line the minimum number of swaps need to sort the given permutation.

Sample Input:

10
3 5 7 2 6 4 9 0 8 1

Sample Output:

9

#include<iostream>
using namespace std;
int a[100001];
int main(){
   int n;
   cin>>n;
   int t;
   for(int i=0;i<n;i++){
      cin>>t;
      a[t]=i;
   }
   int cnt=0;
   for(int i=1;i<n;i++){
      if(i!=a[i]){
         while(a[0]!=0){
            swap(a[0],a[a[0]]);
            cnt++;
         }
         if(i!=a[i]){
            swap(a[0],a[i]);
            cnt++;
         }
      }
   }
   cout<<cnt;
   
   return 0;
}
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