Update RemoveDuplicatesFromSortedArray.java

Author: amankumar100

src/main/java/com/thealgorithms/others/RemoveDuplicatesFromSortedArray.java

@@ -1,75 +1,41 @@
 package com.thealgorithms.others;
 
-import java.util.Scanner;
-
 /**
- * Remove duplicates from sorted array.
- *
- * <p>
- * Given an integer array nums sorted in non-decreasing order, remove the
- * duplicates in-place such that each unique element appears only once.
- * The relative order of the elements should be kept the same. Then return
- * the number of unique elements in nums.
+ * Removes duplicates from a sorted integer array in-place
+ * using the two-pointer technique and O(1) extra space.
  *
  * <p>
+ * Example:
+ * Input:  [1, 1, 2, 2, 3]
+ * Output: 3, and the array becomes [1, 2, 3, _, _]
+ * </p>
  */
 public final class RemoveDuplicatesFromSortedArray {
 
     private RemoveDuplicatesFromSortedArray() {
-        // private constructor to prevent instantiation
-    }
-
-    /**
-     * Main method with user input.
-     */
-    public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-
-        System.out.println("Enter size of sorted array:");
-        int n = scanner.nextInt();
-
-        if (n <= 0) {
-            System.out.println("Invalid array size.");
-            scanner.close();
-            return;
-        }
-
-        int[] nums = new int[n];
-        System.out.println("Enter " + n + " integers in non-decreasing order:");
-        for (int i = 0; i < n; i++) {
-            nums[i] = scanner.nextInt();
-        }
-
-        int k = removeDuplicates(nums);
-
-        System.out.println("Number of unique elements: " + k);
-        System.out.print("Array after removing duplicates: ");
-        for (int i = 0; i < k; i++) {
-            System.out.print(nums[i] + " ");
-        }
-        System.out.println();
-
-        scanner.close();
+        // Utility class, no instantiation
     }
 
     /**
-     * Removes duplicates from a sorted array in-place using O(1) space.
+     * Removes duplicates from a sorted array in-place.
      *
-     * @param nums The input sorted array
-     * @return The number of unique elements
+     * @param nums the sorted input array (non-decreasing order)
+     * @return the number of unique elements
      */
     public static int removeDuplicates(int[] nums) {
         if (nums == null || nums.length == 0) {
             return 0;
         }
 
-        int j = 0; // points to last unique element
+        int j = 0; // Pointer for the last unique element
+
         for (int i = 1; i < nums.length; i++) {
             if (nums[j] != nums[i]) {
                 j++;
                 nums[j] = nums[i];
             }
         }
+
         return j + 1;
     }
 }