minimum number of swaps required to sort the array.cpp

#include<bits/stdc++.h> 
  
using namespace std; 
  
// Function returns the minimum number of swaps 
// required to sort the array 
int minSwaps(int arr[], int n) 
{ 
    // Create an array of pairs where first 
    // element is array element and second element 
    // is position of first element 
    pair<int, int> arrPos[n]; 
    for (int i = 0; i < n; i++) 
    { 
        arrPos[i].first = arr[i]; 
        arrPos[i].second = i; 
    } 
  
    // Sort the array by array element values to 
    // get right position of every element as second 
    // element of pair. 
    sort(arrPos, arrPos + n); 
  
    // To keep track of visited elements. Initialize 
    // all elements as not visited or false. 
    vector<bool> vis(n, false); 
  
    // Initialize result 
    int ans = 0; 
  
    // Traverse array elements 
    for (int i = 0; i < n; i++) 
    { 
        // already swapped and corrected or 
        // already present at correct pos 
        if (vis[i] || arrPos[i].second == i) 
            continue; 
  
        // find out the number of  node in 
        // this cycle and add in ans 
        int cycle_size = 0; 
        int j = i; 
        while (!vis[j]) 
        { 
            vis[j] = 1; 
  
            // move to next node 
            j = arrPos[j].second; 
            cycle_size++; 
        } 
  
        // Update answer by adding current cycle.  
        if (cycle_size > 0) 
        { 
            ans += (cycle_size - 1); 
        } 
    } 
  
    // Return result 
    return ans; 
} 
  
// Driver program to test the above function 
int main() 
{ 
    int arr[] = {1, 5, 4, 3, 2}; 
    int n = (sizeof(arr) / sizeof(int)); 
    cout << minSwaps(arr, n); 
    return 0; 
} 
//
//Output:
//2