Create Queue-Reverse the First K Elements in the Queue

Author: mmuskan22

Queue-Reverse the First K Elements in the Queue

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+For a given queue containing all integer data, reverse the first K elements.
+You have been required to make the desired change in the input queue itself.
+Example:
+alt txt
+
+For the above input queue, if K = 4 then after reversing the first 4 elements, the queue will be updated as:
+alt txt
+
+Input Format :
+The first line of input would contain two integers N and K, separated by a single space. They denote the total number of elements in the queue and the count with which the elements need to be reversed respectively.
+
+The second line of input contains N integers separated by a single space, representing the order in which the elements are enqueued into the queue.
+Output Format:
+The only line of output prints the updated order in which the queue elements are dequeued, all of them separated by a single space. 
+Note:
+You are not required to print the expected output explicitly, it has already been taken care of. Just make the changes in the input queue itself.
+Constraints :
+1 <= N <= 10^6
+1 <= K <= N
+-2^31 <= data <= 2^31 - 1
+
+ Time Limit: 1sec
+Sample Input 1:
+5 3
+1 2 3 4 5
+Sample Output 1:
+3 2 1 4 5
+Sample Input 2:
+7 7
+3 4 2 5 6 7 8
+Sample Output 2:
+8 7 6 5 2 4 3
+
+*******************************************Code*********************************************
+import java.util.*;
+
+public class Solution {
+
+	public static Queue<Integer> reverseKElements(Queue<Integer> input, int k) {
+		
+		Queue<Integer> q1=new LinkedList<>();
+		for(int i=0;i<k;i++)
+		{
+			q1.add(input.poll());
+		}
+		Collections.reverse((List<?>)q1);
+		int len=input.size();
+		for(int i=0;i<len;i++)
+		{
+			q1.add(input.poll());
+		}
+		return q1;
+	}
+	public static Queue<Integer> reverseQueue(Queue<Integer> input)
+	{
+		if (input.size() <= 1)
+			return input;
+		int f = input.poll();
+		reverseQueue(input);
+		input.add(f);
+		return input;
+	}
+}