2. Value equal to index value

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2. Value equal to index value


Problem link :- click here


package program;

import java.util.ArrayList;
import java.util.List;

public class Searching__2
{

	/*
	 	Given an array arr[] of n positive integers. Our task is to find the elements 
	 	whose value is equal to that of its index value.
	 			n = 5	arr[] = {15, 2, 45, 12, 7}
	 		output : 2
	 		
	 	lets iterate through the array and add all the elements that are equal to their 
	 	indices to a ArrayList and return the array list
	 */
	
	static List<Integer> valueEqualToIndex(int arr[], int n)
	{
		List<Integer> result  = new ArrayList<>();
		
		for(int i=0; i<n; i++)
		{
			if(arr[i] == i+1)
				result.add(arr[i]);
		}
		
		return result;
	}
	
	public static void main(String[] args)
	{
		int arr[] = {1, 2, 45, 4, 7};
		
		List<Integer> ans = valueEqualToIndex(arr, arr.length);
		System.out.println("Elements whose values are equal to indices are : \n\t\t" + ans);
	}

}

Time complexity :- O(n)
Space complexity :- O(1)

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