Subsequence Permutation.cpp

/* 

    Solution by Rahul Surana

    ***********************************************************

This is Testing Workspace to learn and know about something new 

    1. euclidean gcd
    2. fast exponention  

    ***********************************************************
*/



#include <bits/stdc++.h>
#define ll          long long
#define vl          vector<ll>
#define vi          vector<int>
#define pi          pair<int,int>
#define pl          pair<ll,ll>
#define all(a)      a.begin(),a.end()
#define mem(a,x)    memset(a,x,sizeof(a))
#define pb          push_back
#define mp          make_pair
#define F           first
#define S           second
#define FOR(i,a)     for(int i = 0; i < a; i++)
#define trace(x)    cerr<<#x<<" : "<<x<<endl;
#define trace2(x,y) cerr<<#x<<" : "<<x<<" | "<<#y<<" : "<<y<<endl;
#define trace3(x,y,z) cerr<<#x<<" : "<<x<<" | "<<#y<<" : "<<y<<" | "<<#z<<" : "<<z<<endl;
#define fast_io     std::ios::sync_with_stdio(false),cin.tie(NULL),cout.tie(NULL)
 
using namespace std;
int inf=1e9+7, MOD=1e9+7;


int ar[41];

int main()
{
	fast_io;
    int t=1;
    cin >> t;
    while(t--) {
        int n;
        cin >> n;
        string s;
        cin >> s;
        string t = s;
        sort(t.begin(),t.end());
        int c = 0;
        FOR(i,s.length()) if(t[i] == s[i]) c++;
        cout << n-c << "\n";
    }

}