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Java Array Exercises: Find all Pairs of elements in an array whose sum is equal to a specified number

Java Array: Exercise-22 with Solution

Write a Java program to find all pairs of elements in an array whose sum is equal to a specified number.

Pictorial Presentation:

Java Array Exercises: Pairs of elements in an array whose sum is equal to a specified number

Sample Solution:

Java Code :

public class Exercise22 {
static void  pairs_value(int inputArray[], int inputNumber)
  {
  System.out.println("Pairs of elements and their sum : ");
 
  for (int i =  0; i < inputArray.length; i++)
  {
  for (int j  = i+1; j < inputArray.length; j++)
  {
  if(inputArray[i]+inputArray[j] == inputNumber)
  {
  System.out.println(inputArray[i]+" + "+inputArray[j]+" =  "+inputNumber);
  }
  }
  }
  }
  
  public static void  main(String[] args)
  {
  pairs_value(new int[] {2, 7, 4, -5, 11, 5, 20}, 15);
  
  pairs_value(new int[] {14, -15, 9, 16, 25, 45, 12, 8}, 30);
  
  }
}

Sample Output: 

Pairs of elements and their sum :                                                                             
4 + 11 = 15                                                                                                
-5 + 20 = 15                                                                                                
Pairs of elements and their sum :                                                                             
14 + 16 = 30                                                                                                
-15 + 45 = 30

Flowchart:

Flowchart: Java exercises: Find all pairs of elements in an array whose sum is equal to a specified number

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Java Code Editor:

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Next: Write a Java program to test the equality of two arrays.

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Java: Tips of the Day

Syntax for creating a two-dimensional array in Java

Try the following : 

int[][] multi = new int[5][10];

... which is a short hand for something like this:

int[][] multi = new int[5][];
multi[0] = new int[10];
multi[1] = new int[10];
multi[2] = new int[10];
multi[3] = new int[10];
multi[4] = new int[10];

Note that every element will be initialized to the default value for int, 0, so the above are also equivalent to:

int[][] multi = new int[][]{
  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
  { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};

Ref: https://bit.ly/3vYSxFz