Step by Step solution about How to resolve the algorithm Range extraction step by step in the Java programming language

This Java program performs range extraction from an integer array by grouping consecutive numbers into ranges. It processes elements in the array and identifies gaps between them. When a gap of more than one is encountered, it prints a range using the start and end values of the consecutive elements. Otherwise, it prints individual elements.

Here's how it works:

1. Initialization:

   • Define an integer array arr with values representing a set of integers.
   • Initialize variables len to the length of the array, idx to 0, and idx2 to 0.

2. Loop through the Array:

   • The outer while loop (line 10) iterates through the array arr using the idx variable.

3. Check for Consecutive Elements:

   • Within the outer loop, there's an inner while loop (line 11) that increments idx2 until a gap of more than one is found between consecutive elements in arr. This checks if there are consecutive elements.

4. Handle Range and Individual Elements:

   • If the difference between arr[idx2] and arr[idx2 - 1] is greater than 1, it means there's a gap of more than one. In this case, a range is printed using the start value arr[idx] and the end value arr[idx2 - 1], followed by a comma (line 13). Then, idx is updated to idx2 to continue processing the next range.
   • If the gap is not more than one, it means there are no consecutive elements. In this case, a loop iterates from idx to idx2 printing individual elements, each followed by a comma (line 16).

5. Continue Processing:

   • The outer loop continues incrementing idx and repeating the process until the end of the array is reached.

6. Output:

   • The program prints the extracted ranges and individual elements in the format specified in the problem description.

In the provided example, the input array contains a set of integers, and the output would be a combination of ranges and individual elements, such as:

0,1,2,4-8,11-12,14-25,27-30,32-33,35-39

public class RangeExtraction {

    public static void main(String[] args) {
        int[] arr = {0, 1, 2, 4, 6, 7, 8, 11, 12, 14,
            15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
            25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
            37, 38, 39};

        int len = arr.length;
        int idx = 0, idx2 = 0;
        while (idx < len) {
            while (++idx2 < len && arr[idx2] - arr[idx2 - 1] == 1);
            if (idx2 - idx > 2) {
                System.out.printf("%s-%s,", arr[idx], arr[idx2 - 1]);
                idx = idx2;
            } else {
                for (; idx < idx2; idx++)
                    System.out.printf("%s,", arr[idx]);
            }
        }
    }
}