Leetcode + hackerrank good questions

Question link- 

https://www.hackerrank.com/challenges/minimum-swaps-2/problem

You are given an unordered array consisting of consecutive integers  [1, 2, 3, ..., n] without any duplicates. You are allowed to swap any two elements. Find the minimum number of swaps required to sort the array in ascending order.

Example

Perform the following steps:

i   arr                         swap (indices)

0   [7, 1, 3, 2, 4, 5, 6]   swap (0,3)

1   [2, 1, 3, 7, 4, 5, 6]   swap (0,1)

2   [1, 2, 3, 7, 4, 5, 6]   swap (3,4)

3   [1, 2, 3, 4, 7, 5, 6]   swap (4,5)

4   [1, 2, 3, 4, 5, 7, 6]   swap (5,6)

5   [1, 2, 3, 4, 5, 6, 7]

It took  swaps to sort the array.

Function Description

Complete the function minimumSwaps in the editor below.

minimumSwaps has the following parameter(s):

int arr[n]: an unordered array of integers

Returns

int: the minimum number of swaps to sort the array

Input Format

The first line contains an integer, , the size of .

The second line contains  space-separated integers .

Constraints

Sample Input 0

4

4 3 1 2

Sample Output 0

3

Explanation 0

Given array 

After swapping  we get 

After swapping  we get 

After swapping  we get 

So, we need a minimum of  swaps to sort the array in ascending order.

Sample Input 1

5

2 3 4 1 5

Sample Output 1

3

Explanation 1

Given array 

After swapping  we get 

After swapping  we get 

After swapping  we get 

So, we need a minimum of  swaps to sort the array in ascending order.

Sample Input 2

7

1 3 5 2 4 6 7

Sample Output 2

3

Explanation 2

Given array 

After swapping  we get 

After swapping  we get 

After swapping  we get 

So, we need a minimum of  swaps to sort the array in ascending order.

SOLUTION -

import java.io.*;

import java.math.*;

import java.security.*;

import java.text.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.regex.*;

public class Solution {

    // Complete the minimumSwaps function below.

    static int minimumSwaps(int[] arr) {

        int count = 0;

        int start = 1;

        for(int i=0;i<arr.length;i++)

        {

            if(arr[i]==start)

            {

            }

            else

            {

                int val = start;

                int index = find(arr,val);

                //System.out.println(val+","+index);

                int val2 = arr[i];

                //System.out.println("replaceing:" +val+",with"+val2+",indexes:"+index+","+i);

                arr[i] = val;

                arr[index] = val2;

                count = count+1;

                

            }

            start = start+1;

        }

        return count;

    }

    static int find(int arr[],int no)

    {

        for(int i=0;i<arr.length;i++)

        {

            if(no==arr[i])

            {

                return i;

            }

        }

        return 0;

    }

    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {

        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int n = scanner.nextInt();

        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        int[] arr = new int[n];

        String[] arrItems = scanner.nextLine().split(" ");

        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int i = 0; i < n; i++) {

            int arrItem = Integer.parseInt(arrItems[i]);

            arr[i] = arrItem;

        }

        int res = minimumSwaps(arr);

        bufferedWriter.write(String.valueOf(res));

        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();

    }

}