Min swap required to sort the array

min_inversion.cpp

long countInversions(vector<int> arr) {
    map<int,pair<int,int>> mp;
    int count;
    for(int i=0;i<arr.size();i++){
        mp[arr[i]].first++;
    }
    count = mp.size();
    mp.insert({0,{0,0}});
    for(auto i=mp.begin();i!=mp.end();i++){
        if(count>0){
            count--;
            next(i,1)->second.second = next(i,1)->second.first + i->second.second;
        }
    }
    for(int i=0;i<arr.size();i++){
        count = arr[i];
        arr[i] = mp[arr[i]].second - mp[arr[i]].first;
        mp[count].first = mp[count].first- 1;
    }
    int ans =0;
    int j,temp;
    for(int i=0;i<arr.size();i++){
        if(arr[i]!=-1){
            count=0;
            j = arr[i];
            while(j!=i){
                count++;
                temp = arr[j];
                arr[j] = -1;
                j = temp;
            }
            ans += count;
        }
    }
    return ans;
}