Add files via upload (#275)

Author: nayan22k

Java/LeftRotateArrayByD.java

@@ -0,0 +1,60 @@
+package com.company;
+
+public class LeftRotateArrayByD {
+
+    //Reversal Algorithm-->
+    static void reverse(int[] arr, int low, int high){
+        int temp=0;
+        while (low<high) {
+            temp = arr[low];
+            arr[low] = arr[high];
+            arr[high] = temp;
+            low++;
+            high--;
+        }
+    }
+
+    static void leftRotate(int[] arr, int d){
+        if (d==0)
+            return;
+
+        int n=arr.length;
+        reverse(arr,0,d-1);
+        reverse(arr, d,n-1);
+        reverse(arr,0,n-1);
+    }
+
+    // Better Method-->
+
+//    static void leftRotate(int[] arr, int d){
+//        int[] temp = new int[d];
+//        for (int i=0; i<d; i++)
+//            temp[i]=arr[i];
+//        for (int i=d; i< arr.length; i++)
+//            arr[i-d]=arr[i];
+//        for (int i=0; i<d; i++)
+//            arr[arr.length-d+1]=temp[i];
+//    }
+
+    // Naive Method-->
+
+//    static void leftRotateOne(int[] arr){
+//        int n = arr.length;
+//        int temp = arr[0];
+//        for (int i=1; i<arr.length; i++)
+//            arr[i-1]=arr[i];
+//        arr[n-1]=temp;
+//    }
+//    static void LeftRotate(int[] arr, int d){
+//        for (int i=0; i<d; i++)
+//            leftRotateOne(arr);
+//    }
+    public static void main(String[] args) {
+        int[] arr = new int[]{1,2,3,4,5};
+        int d = 2;
+        int n = arr.length;
+        leftRotate(arr, 2);
+        for (int i=0; i<n; i++)
+            System.out.print(arr[i] + " ");
+    }
+}