Optimal sort

#include <bits/stdc++.h>

using namespace std;
#define int long long
#define vout(x) for(int i=0;i<(long long)x.size();i++) printf("%lld ",x[i]);
#define REP(i,a,b) for (int i = a; i <= b; i++)

// g++ <filename>.cpp -g -Wall -Wextra -DDEBUG -o <executable>

// copied from: https://codeforces.com/blog/entry/79024
// === Debug macro starts here ===

int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) {++recur_depth; auto x_=x; --recur_depth; cerr<<string(recur_depth, '\t')<<"\e[91m"<<__func__<<":"<<__LINE__<<"\t"<<#x<<" = "<<x_<<"\e[39m"<<endl;}
#else
#define dbg(x)
#endif
template<typename Ostream, typename Cont>
typename enable_if<is_same<Ostream,ostream>::value, Ostream&>::type operator<<(Ostream& os,  const Cont& v){
	os<<"[";
	for(auto& x:v){os<<x<<", ";}
	return os<<"]";
}
template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os,  const pair<Ts...>& p){
	return os<<"{"<<p.first<<", "<<p.second<<"}";
}

// === Debug macro ends here ===

signed main() {
    
    int n;
    cin >> n;

    vector<pair<int,int>> numbers(n);
    
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        numbers[i].first = a;
        numbers[i].second = i;
    }

    sort(numbers.begin(), numbers.end());

    int count = 0;
    vector<bool> visited(n, false);

    for (int i = 0; i < n; i++) {

        if (numbers[i].second == i || visited[i]) continue;
    
        int cycle_count = 0;
        int j = i;

        while (visited[j] == false) {
            visited[j] = true;

            j = numbers[j].second;
            cycle_count++;
        }

        if (cycle_count > 0) {
            count += cycle_count - 1;
        }
    }

    cout << count << "\n";


    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

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Test 3

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Test 4

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Test 5

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Test 6

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Test 10

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Test 21

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Test 22

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Test 44

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Test 45

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Test 48

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Test 49

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Test 50

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Test 66

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Test 67

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Test 68

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Test 69

Verdict: ACCEPTED

Test 70

Verdict: ACCEPTED