# Java Program to Form Two Numbers (2 digit) with Minimum Sum Using Array Elements

In the previous article, we have seen Java Program to Form Two Numbers (of 2 digit) with Maximum Sum Using Array Elements

In this article, we will see how to form two numbers of 2 digits with minimum sum using array elements in Java programming language.

## Java Program to Form Two Numbers (2 digit) with Minimum Sum Using Array Elements

Prerequisite:

See below articles to know more about Array in Java, array declaration, array instantiation and array initialization.

Base Condition:

1. The number is a 2 digited number (Ex-54, 89, 71 etc.)
2. We have to form 2 numbers using array elements.
3. All the array elements need to be single digited only.

Let’s see different ways to form two numbers of 2 digits with minimum sum.

### Method-1: Java Program to Form Two Numbers (of 2 digits) with Minimum Sum Using Array Elements By Using Sorting

Approach:

• Declare an array and with single digit numbers as array elements.
• Call the user defined method findMinimum().
• Inside method, sort the array in ascending order.
• So first element of array is smallest element in array and elements are ordered in increasing order.
• So combine index-0 and index-1 element which is the 1st smallest number that can be formed using array elements.
• Next combine index-0 and index-2 element which is the 2nd smallest number that can be formed using array elements.
• As we have two smallest numbers so sum will be minimum.
• So, return those two numbers.

Program:

import java.util.Arrays;
import java.util.Comparator;

class Main
{
// Find two numbers with a minimum sum formed by digits of an array
public static void findMainimum(Integer[] input)
{

// sort the array in ascending order
Arrays.sort(input);

//find first number
int x = 0;
x = x * 10 + input[0];
x = x * 10 + input[1];

//find second number
int y=0;
y = y * 10 + input[0];
y = y * 10 + input[2];

// print x and y
System.out.println("The two numbers formed by using array elements with minimum sum are " + x + " and " + y);
int sum=x+y;
System.out.println("And the minimum sum is "+sum);
}

public static void main(String[] args)
{
Integer[] input = { 1,5,3,4,5 };

findMinimum(input);
}
}
Output:

The two numbers formed by using array elements with minimum sum are 13 and 14
And the minimum sum is 27

### Method-2: Java Program to Form Two Numbers (of 2 digits) with Minimum Sum Using Array Elements By Finding 1st, 2nd and 3rd Big Element from Array

Approach:

• Take user input of length of array.
• Take input of array elements (only single digits)
• Call the user defined method findSmallest() to find 3 big elements in the array say firstNumber, secondNumber and thirdNumber.
• After getting 3 small elements in the array, inside that findSmallest() method, call findMinNumber() method.
• Inside findMinNumber() method combine firstNumber and secondNumber element which is the 1st smallest number that can be formed using array elements.
• Next combine firstNumber and thirdNumber element which is the 2nd smallest number that can be formed using array elements.
• As we have two smallest numbers so sum will be minimum.
• So, return those two numbers.

Program:

import java.util.Scanner;

public class Main
{
public static void main(String args[])
{
int length = 0;
Scanner sc = new Scanner(System.in);
System.out.println("Enter number of elements in array: ");
//array length taken as input
length = sc.nextInt();
//array declared
int[] arr = new int[length];

//take input of single digited number as array element
System.out.println("Enter elements into array: ");
//taking input of array elements
for (int i = 0; i < length; i++)
{
arr[i] = sc.nextInt();
}

System.out.println("First 3 smallest numbers in array : ");
//calling findSmallest() method
findSmallest(arr);
}

//user defined method to find first 3 smallest element
private static void findSmallest(int[] arr)
{
int firstNumber = arr[0];
int secondNumber = 0;
int thirdNumber = 0;

for (int i = 0; i < arr.length; i++)
{
if (arr[i] < firstNumber)
{
thirdNumber = secondNumber;
secondNumber = firstNumber;
firstNumber = arr[i];
}
else if (arr[i] < secondNumber)
{
thirdNumber = secondNumber;
secondNumber = arr[i];
}
else if (arr[i] < thirdNumber)
{
thirdNumber = arr[i];
}
}

System.out.println("First smallest number : " + firstNumber);
System.out.println("Second smallest number : " + secondNumber);
System.out.println("Third smallest number : " + thirdNumber);

//calling findMinNumber() method
findMinNumber(firstNumber,secondNumber,thirdNumber);
}

//findMinNumber() user defined method to form two numbers whose sum is minimum
public static void findMinNumber(int firstNumber,int secondNumber,int thirdNumber)
{
//find first number
int x = 0;
x = x * 10 + firstNumber;
x = x * 10 + secondNumber;

//find second number
int y = 0;
y = y * 10 + firstNumber;
y = y * 10 + thirdNumber;

// print x and y
System.out.println("The two numbers formed by using array elements with minimum sum are " + x + " and " + y);
int sum=x+y;
System.out.println("And the minimum sum is "+sum);
}
}
Output:

Enter number of elements in array:
6
Enter elements into array:
9 2 5 7 1 4
First 3 smallest numbers in array :
First smallest number : 1
Second smallest number : 2
Third smallest number : 4
The two numbers formed by using array elements with minimum sum are 12 and 14
And the minimum sum is 26

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