Home/Questions/Q 803883
Next
In Process
codemania
  • 0
Asked: 2023-05-27T09:28:35+00:00 In:

Java Program to Find Two Elements whose Sum is Equal to a Given Number

  • 0
Java Program to Find Two Elements whose Sum is Equal to a Given Number
codejava
Share

    1 Answer

    1. This is the Java Program to Find Two Elements whose Sum is Equal to a Given Number.

      Problem Description

      Given an array of n integers and a value, say m. Find out the pairs of elements from the array, whose sum values m.
      Example:
      Array = [ 1, 2, 4, 5, 8, 10, 11] m = 13

      Output :
      {8, 5}
      {11, 2}

      Problem Solution

      Iterate through the array and in a temporary variable, say x, store the difference of the current array element and the value m. Search for value x, in the map, if x is present in the map, then the pair of elements x and the current array element, sums to m, else store x in the map.

      Program/Source Code

      Here is the source code of the Java Program to Find Two Elements whose Sum is Equal to a Given Number. The program is successfully compiled and tested using IDE IntelliJ Idea in Windows 7. The program output is also shown below.

      2. //Java Program to Find Two Elements whose Sum is Equal to a Given Number.
      4. import java.io.BufferedReader;
      5. import java.io.InputStreamReader;
      6. import java.util.HashMap;
      8. public class PairsHavingGivenSum {
      9.     // Function to print the pair of elements having a given sum
      10.     static void printPairs(int[] array,int sum)
      11.     {
      12.         HashMap<Integer,Integer> obj=new HashMap<>();
      13.         int i,search;
      14.         System.out.println("The pairs having sum "+sum+" are");
      15.         for(i=0;i<array.length;i++){
      16.             search=sum-array[i];
      17.             if(obj.containsValue(search)){
      18.                 System.out.println(array[i]+" and "+search);
      19.             }
      20.             else
      21.             {
      22.                 obj.put(i,array[i]);
      23.             }
      24.         }
      25.     }
      26.     // Main function to read the input
      27.     public static void main(String[] args) {
      28.         BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
      29.         int size;
      30.         System.out.println("Enter the size of the array");
      31.         try{
      32.             size=Integer.parseInt(br.readLine());
      33.         }
      34.         catch(Exception e)
      35.         {
      36.             System.out.println("Invalid Input");
      37.             return;
      38.         }
      39.         int[] array=new int[size];
      40.         System.out.println("Enter array elements");
      41.         int i;
      42.         for(i=0;i<array.length;i++){
      43.             try{
      44.                 array[i]=Integer.parseInt(br.readLine());
      45.             }
      46.             catch(Exception e)
      47.             {
      48.                 System.out.println("Invalid element. Enter it again");
      49.                 i--;
      50.             }
      51.         }
      52.         int sum;
      53.         System.out.println("Enter the sum you want to look for");
      54.         try{
      55.             sum=Integer.parseInt(br.readLine());
      56.         }
      57.         catch(Exception e)
      58.         {
      59.             System.out.println("Invalid Input");
      60.             return;
      61.         }
      62.         printPairs(array,sum);
      63.     }
      64. }
      Program Explanation
      1. In function printPairs(), firstly a hashmap is created HashMap<integer,integer> obj=new HashMap<>().
      
2. The loop for(i=0; i<array.length; i++), sets the value search to sum – array[i] in each iteration.
      
3. The condition if(obj.containsValue(search)) looks for the variable search in the hashmap.
      
4. If it is present, then the present element and the element search has the given sum in the array.
      
5. Otherwise, the value search is added to the hashmap.</integer,integer>
      • 0
    You must login to add an answer.
    Need An Account, 
    Related Questions