Ttykuu

I am a beginner in programming. To rotate the array to left, I have written the below code. Please point out how to optimize the code and anything I am doing which is not good programming practice.

package arrays;

import java.util.Scanner;

public class ArrayLeftRotation 

 public static int[] LeftRotation(int numberOfLeftRotations, int[] a, int[] b) 

 int n1 = numberOfLeftRotations, n2 = numberOfLeftRotations;
 /*
 * First for loop Given array a0=1,a1=2,a3=4,a4=5,a5=6,a6=7; First we
 * are shifting the first 3 elements to last 3 slots and the array looks
 * like below a0=1,a1=2,a2=3,a3=,a4=1,a5=2,a6=3; The above step we are
 * performing through below logic
 * a[array.length-numberOfLeftRotations]=b[i]; GIVEN ARRAY LENGTH -
 * NUMBER OF LEFT ROTATIONS IS THE STARTING POINT TO MOVE THE FIRST
 * ELEMENTS OF THE ARRAY TO LAST
 */
 for (int i = 0; i < numberOfLeftRotations; i++) 
 a[a.length - n1] = b[i];
 n1--;
 
 /*
 * Second for loop After executing the above loop the array look like
 * below a0=1,a1=2,a2=3,a3=,a4=1,a5=2,a6=3; now except the last three
 * slots every thing needs to be changed
 * a0=4,a1=5,a2=6,a3=7,a4=1,a5=2,a6=3; we achieved the above array
 * result through below logic a[i]=b[numberOfLeftRotations]; REPLACED
 * THE REMAINING SLOTS WITH THE VALUES STARTING FROM
 * NUMBEROFLEFTROTATIONS
 */
 for (int i = 0; i < a.length - numberOfLeftRotations; i++) 
 a[i] = b[n2];
 n2++;
 
 return a;
 

 public static int[] LeftRotation(int numberOfLeftRotations, int[] a) 

 return a;

 

 public static int[] printArray(int[] a) 

 for (int i = 0; i < a.length; i++) 
 System.out.println(a[i]);
 
 return a;
 

 public static void main(String[] args) 
 // TODO Auto-generated method stub
 Scanner sc = new Scanner(System.in);
 System.out.println("Enter number of Left Rotations need to be done");
 int l = sc.nextInt();
 System.out.println("Enter number of elements in an array");
 int e = sc.nextInt();
 int[] a = new int[e];

 for (int i = 0; i < a.length; i++) 
 a[i] = sc.nextInt();
 

 int[] b = a.clone();

 LeftRotation(l, a, b);
 printArray(a);