added array rotation 3 approaches

Author: GauravWalia19

Java/Data-Structures/ARRAYS/MISC/ArrayRotation1.java

@@ -0,0 +1,42 @@
+/*
+ *  ARRAY ROTATION USING TEMP ARRAY
+ *  LEFT ROTATE TO 2
+ */
+import java.util.*;
+public class ArrayRotation1
+{
+    public static void main(String[] args)
+    {
+        Scanner in = new Scanner(System.in);
+        int[] arr = {1,2,3,4,5,6,7};
+        int shift=2;
+
+        rotate(arr,shift,arr.length);
+        
+        in.close();
+    }
+    public static void rotate(int[] arr,int d,int n)
+    {
+        int[] temp = new int[d];
+        //copy arr 2 elements to temp
+        for(int i=0;i<temp.length;i++)
+        {
+            temp[i] = arr[i];
+        }
+        //shifting array
+        for(int i=0;i<arr.length-d;i++)
+        {
+            arr[i]=arr[i+d];
+        }
+        //copy temp array to array
+        for(int i=0;i<d;i++)
+        {
+            arr[i+arr.length-d] =temp[i];
+        }
+        for(int i=0;i<arr.length;i++)
+        {
+            System.out.print(arr[i]+" ");
+        }
+        System.out.println();
+    }   
+}

Java/Data-Structures/ARRAYS/MISC/ArrayRotation2.java

@@ -0,0 +1,35 @@
+/*
+ *  ARRAY ROTATION USING ONE ELEMENT
+ *  LEFT ROTATE BY 2
+ */
+import java.util.*;
+public class ArrayRotation2
+{
+    public static void main(String[] args)
+    {
+        Scanner in = new Scanner(System.in);
+        int[] arr={1,2,3,4,5,6,7};  
+        int shift=3;     
+        rotate(arr, shift, arr.length);
+
+        //printing array
+        for(int i=0;i<arr.length;i++)
+        {
+            System.out.print(arr[i]+" ");
+        }
+        in.close();
+    }
+    public static void rotate(int[] arr,int d,int n)
+    {
+        //we can shift one by one    
+        for(int i=0;i<d;i++)
+        {
+            int temp = arr[0];
+            for(int j=0;j<n-1;j++)
+            {
+                arr[j]=arr[j+1];
+            }
+            arr[n-1]=temp;
+        }
+    }
+}

Java/Data-Structures/ARRAYS/MISC/jugglingAlgo.java

@@ -0,0 +1,44 @@
+abstract class jugglingAlgo
+{
+    public static void main(String[] args)
+    {
+        int[] arr = {1,2,3,4,5,6,7,8,9};
+        leftRotation(arr,3);
+        for(int i=0;i<arr.length;i++)
+        {
+            System.out.print(arr[i] + " ");
+        }        
+        System.out.println();
+    }
+    public static int[] leftRotation(int[] arr,int k)
+    {
+        int set = gcd(arr.length, k);
+
+        for(int i=0;i<set;i++)
+        {
+            int temp = arr[i];
+            int j=i;
+            while(true)
+            {
+                int d = (j+k) % arr.length;
+                
+                if(d==i)
+                {
+                    break;
+                }
+                arr[j] = arr[d];
+                j=d;
+            }
+            arr[j] = temp;
+        }
+        return arr;
+    }
+    public static int gcd(int a,int b)
+    {
+        if(b==0)
+        {
+            return a;
+        }
+        return gcd(b,a%b);
+    }
+}

Java/README.md

@@ -17,6 +17,10 @@
 * MISC
   * JAGGED ARRAY
   * [SPIRAL ORDER MATRIX](Data-Structures/ARRAYS/MISC/spiralOrder.java)
+  * Rotate 1D array to left by K
+    * APPROACH 1: [rotate array using temp array](Data-Structures/ARRAYS/MISC/ArrayRotation1.java)
+    * APPROACH 2: [rotate array by rotating one element](Data-Structures/ARRAYS/MISC/ArrayRotation2.java)
+    * APPROACH 3: [rotate array using Juggling Algorithm](Data-Structures/ARRAYS/MISC/jugglingAlgo.java)
 
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