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Java Array Exercises: Form the largest number from a given list of non negative integers

Java Array: Exercise-71 with Solution

Write a Java program to form the largest number from a given list of non negative integers.

Example:
Input :
nums = {1, 2, 3, 0, 4, 6}
Output:
Largest number using the said array numbers: 643210

Sample Solution:

Java Code:

import java.util.*;
public class solution {
	
 public static String  largest_Numbers(int[] num) {
        String[] array_nums = Arrays.stream(num).mapToObj(String::valueOf).toArray(String[]::new);
        Arrays.sort(array_nums, (String str1, String str2) -> (str2 + str1).compareTo(str1 + str2));
        return Arrays.stream(array_nums).reduce((a, b) -> a.equals("0") ? b : a + b).get();
    }	
	
  public static void main(String[] args)
  {
    int[] nums = {1, 2, 3, 0, 4, 6};
	System.out.printf("\nOriginal array: "+Arrays.toString(nums));	
	System.out.printf("\nLargest number using the said array numbers: "+largest_Numbers(nums));
   }  
}

Sample Output:

Original array: [1, 2, 3, 0, 4, 6]
Largest number using the said array numbers: 643210

Flowchart:

Flowchart: Form the largest number from a given list of non negative integers.

Java Code Editor:

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Previous: Write a Java program to find the smallest length of a contiguous subarray of which the sum is greater than or equal to specified value. Return 0 instead.
Next: Write a Java program to find and print one continuous subarray (from a given array of integers) that if you only sort the said subarray in ascending order then the entire array will be sorted in ascending order.

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Java: Tips of the Day

Different between parseInt() and valueOf() in java?

Well, the API for Integer.valueOf(String) does indeed say that the String is interpreted exactly as if it were given to Integer.parseInt(String). However, valueOf(String) returns a new Integer() object whereas parseInt(String) returns a primitive int.

If you want to enjoy the potential caching benefits of Integer.valueOf(int), you could also use this eyesore:

Integer k = Integer.valueOf(Integer.parseInt("123"))

Now, if what you want is the object and not the primitive, then using valueOf(String) may be more attractive than making a new object out of parseInt(String) because the former is consistently present across Integer, Long, Double, etc.

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