w3resource

Java Array Exercises: Check if a sub-array is formed by consecutive integers from a given array of integers

Java Array: Exercise-57 with Solution

Write a Java program to check if a sub-array is formed by consecutive integers from a given array of integers.

Example:
Input :
nums = { 2, 5, 0, 2, 1, 4, 3, 6, 1, 0 }
Output:
The largest sub-array is [1, 7]
Elements of the sub-array: 5 0 2 1 4 3 6

Sample Solution:

Java Code:

import java.lang.Math;
import java.util.Arrays;
class solution
{
	static boolean is_consecutive(int nums[], int i, int j, int min, int max)
	{
		if (max - min != j - i) {
			return false;
		}

		boolean check[] = new boolean[j - i + 1];

		for (int k = i; k <= j; k++)
		{
			if (check[nums[k] - min]) {
				return false;
			}

			check[nums[k] - min] = true;
		}
	
		return true;
	}
	
	public static void find_Max_SubArray(int[] nums)
	 {
		int len = 1;
		int start = 0, end = 0;

		for (int i = 0; i < nums.length - 1; i++)
		{
			int min_val = nums[i], max_val = nums[i];
	
			for (int j = i + 1; j < nums.length; j++)
			{
				min_val = Math.min(min_val, nums[j]);
				max_val = Math.max(max_val, nums[j]);
	
				if (is_consecutive(nums, i, j, min_val, max_val))
				{
					if (len < max_val - min_val + 1)
					{
						len = max_val - min_val + 1;
						start = i;
						end = j;
					}
				}
			}
		}
	
		System.out.println("The largest sub-array is [" + start + ", "
							+ end + "]");
		System.out.print("Elements of the sub-array: ");
	    for (int x = start; x <= end; x++)
	     {
			
		  System.out.print(nums[x]+" ");			
		 }	
	}

	public static void main (String[] args)
	{
		int[] nums = { 2, 5, 0, 2, 1, 4, 3, 6, 1, 0 };
        System.out.println("Original array: "+Arrays.toString(nums)); 
		find_Max_SubArray(nums);
	}
} 

Sample Output:

                                                                              
Original array: [2, 5, 0, 2, 1, 4, 3, 6, 1, 0]
The largest sub-array is [1, 7]
Elements of the sub-array: 5 0 2 1 4 3 6 

Flowchart:

Flowchart: Check if a sub-array is formed by consecutive integers from a given array of integers

Java Code Editor:

Improve this sample solution and post your code through Disqus

Previous: Write a Java program to sort a given binary array in linear times.
Next: write a Java program to merge elements of A with B by maintaining the sorted order.

What is the difficulty level of this exercise?



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