Java Array Exercises: Replace every element with the next greatest element in a given array of integers

Java Array: Exercise-53 with Solution

Write a Java program to replace every element with the next greatest element (from right side) in a given array of integers. There is no element next to the last element, therefore replace it with -1.

Sample Solution:

Java Code:

import java.io.*;
import java.util.Arrays;
public class Main 
{
   public static void main (String[] args)
    {
        int nums[] = {45, 20, 100, 23, -5, 2, -6};
		int result[];
		System.out.println("Original Array ");
        System.out.println(Arrays.toString(nums));

        result = next_greatest_num(nums);
        System.out.println("The modified array:");
        System.out.println(Arrays.toString(result));
    }
 
    static int [] next_greatest_num(int arr_nums[])
    {
        int size = arr_nums.length;
        int max_from_right_num =  arr_nums[size-1];
        arr_nums[size-1] = -1;
 
        for (int i = size-2; i >= 0; i--)
        {
            int temp = arr_nums[i];
            arr_nums[i] = max_from_right_num;
            if(max_from_right_num < temp)
            max_from_right_num = temp;
        }
		return arr_nums;
    } 
}

Sample Output:

                                                                              
Original Array 
[45, 20, 100, 23, -5, 2, -6]
The modified array:
[100, 100, 23, 2, 2, -6, -1]

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