Optimal sort

input/code.cpp: In function 'int main()':
input/code.cpp:53:9: warning: variable 'index' set but not used [-Wunused-but-set-variable]
   53 |     int index = 0;
      |         ^~~~~

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

void dfs_i(int u, int v, int dist, vector<pair<int, int>>& parent, const vector<vector<int>>& adj, vector<bool>& vis)
{
    if (vis[v] || adj[v].size() == 0) return;
    vis[v] = true;
    parent[v] = make_pair(u, dist);
    parent[u].second++;
    if (adj[v].size() > 0)
    {
        dfs_i(u, adj[v][0], ++dist, parent, adj, vis);
    }
}

int dfs(const vector<vector<int>>& adj, vector<pair<int, int>>& parent)
{
    int n = adj.size();
    vector<bool> vis(n, false);
    int count = 0;
    for (int i = 1; i < n; i++)
    {
        bool unique = true;
        if (vis[i]) unique = false;
        dfs_i(i, i, 0, parent, adj, vis);
        if (unique && adj[i].size() > 0)
        {
            count += parent[i].second - 1;
        }
    }
    return count;
}

int main()
{
    int n;
    cin >> n;
    vector<int> inputArray(n);
    int max = 0;
    for (int i = 0; i < n; i++)
    {
        cin >> inputArray[i];
        if (inputArray[i] > max) max = inputArray[i];
    }
    vector<int> sortedArray = inputArray;
    vector<vector<int>> adj(max+1);
    vector<pair<int, int>> parent(max+1);
    
    sort(sortedArray.begin(), sortedArray.end());
    int index = 0;

    for (int i = 0; i < n; i++)
    {
        if (sortedArray[i] != inputArray[i])
        {

            index = inputArray[i];
            adj[inputArray[i]].push_back(sortedArray[i]);
        }
    }
    int count = dfs(adj, parent);
    cout << count << endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

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 7

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Test 8

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Test 9

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Test 10

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Test 11

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Test 12

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Test 13

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Test 14

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Test 15

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Test 16

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Test 17

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Test 18

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Test 19

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Test 20

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Test 21

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Test 22

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Test 23

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Test 24

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Test 25

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Test 26

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Test 27

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Test 28

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Test 29

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Test 30

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Test 70

Verdict: RUNTIME ERROR