Find the All the duplicate elements in an array.

Given an array with multiple duplicate elements print all the duplicate elements once from it in sorted order.

For Example:

Input1: 9

Input2: {3,5,2,4,2,3,9,9,9}

Output: 2,3,9

Explanation:

The explanation is pretty straight forward as in the array:

2 occurs 2 times

3 occurs 2 times and

9 occurs 3 times

So these elements have duplicated records in the array and should be printed.

CODE:

package arrays;

import java.util.HashSet;

import java.util.Scanner;

import java.util.TreeSet;

public class PrintAllDuplicateElementsInSortedOrder

{

     public static void main(String[] args)

     {

     Scanner sc = new Scanner(System.in);

     System.out.println("Enter the length of Array");

     int n = sc.nextInt();

     int ar[] = new int[n];

     System.out.println("Enter the array Elements");

     for (int i = 0; i < n; i++)

     {

        ar[i] = sc.nextInt();

     }

     print(ar);

     }

     public static void print(int ar[])

     {

      HashSet<Integer> hs= new HashSet<>();

      TreeSet<Integer>  ts= new TreeSet<>();

      for(int i:ar)

      {

          boolean check=hs.add(i);

          if(!check)

          {

             ts.add(i);

          }

      }

      //printing the required elements

      for(int i:ts)

      {

          System.out.print(i+" ");

      }

     }

}

OUTPUT:

Enter the length of Array

9

Enter the array Elements

3 5 2 4 2 3 9 9 9

2 3 9

Maximum Sum of a Set of Contiguous Positive Numbers in an Array:

An Array contains random positive as well as negative numbers. It may contain a streak of positive numbers and then a few negative numbers. This behaviour can occur multiple times.

You need to find out the maximum sum out of all streaks of the positive numbers.

For example:

Input1: 6

Input2: {1,2,3-4,3,1}

Output: 6

Input2: 7

Input2: {-1,3,1,2,-1,2,7}

Output: 9

The explanation for First Example :

Input 1: Number of Elements in the array

Input 2: Array Elements

Output: Maximum Sum of a Set of Contagious Positive Number in an Array:

In the first example there are two contagious set of positive numbers:

{1,2,3} and {3,1}. for which the sum is: 6 and 4, so the maximum out of them is 6.

CODE:

package arrays;

import java.util.Scanner;

public class MaximumSumContPositiveNum

     {

     public static void main(String[] args)

     {

     int curSum = 0, maxSum = -1;

     Scanner sc = new Scanner(System.in);

     System.out.println("Enter the length of Array");

     int n = sc.nextInt();

     int ar[] = new int[n];

     System.out.println("Enter the array Elements");

     for (int i = 0; i < n; i++)

     {

          ar[i] = sc.nextInt();

     }

     for (int idx = 0; idx < n; idx++)

     {

          if (ar[idx] >= 0)

          {

               curSum = curSum + ar[idx];

               if (curSum > maxSum)

               {

                    maxSum = curSum;

               }

          } 

          else

          {

               curSum = 0;

          }

     }

     System.out.println("Maximum Sum of a Set of Contagious Positive Number in an Array is " + maxSum);

     }

}

OUTPUT:

Enter the length of Array

7

Enter the array Elements

-1 3 1 2 -1 2 7

Maximum Sum of a Set of Contagious Positive Number in an Array is 9