Remove duplicates in place: done

Author: rampatra

src/main/java/com/leetcode/arrays/RemoveDuplicates.java

@@ -0,0 +1,60 @@
+package com.leetcode.arrays;
+
+import java.util.Arrays;
+
+/**
+ * Level: Easy
+ * Problem Link: https://leetcode.com/problems/remove-duplicates-from-sorted-array/
+ * Problem Description:
+ * Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.
+ * <p>
+ * Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
+ * Example 1:
+ * <p>
+ * Given nums = [1,1,2]
+ * <p>
+ * Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
+ * <p>
+ * It doesn't matter what you leave beyond the returned length.
+ *
+ * @author rampatra
+ * @since 2019-04-24
+ */
+public class RemoveDuplicates {
+
+    /**
+     * Time complexity: O(n)
+     * where,
+     * n = no. of elements in the array
+     * <p>
+     * Runtime: <a href="https://leetcode.com/submissions/detail/224719750/">1 ms</a>.
+     *
+     * @param nums
+     * @return
+     */
+    public static int removeDuplicatesInSortedArray(int[] nums) {
+        int insertIndex = 0;
+
+        for (int i = 1; i < nums.length; i++) {
+            if (nums[i] != nums[i - 1]) {
+                nums[++insertIndex] = nums[i];
+            }
+        }
+
+        return insertIndex + 1;
+    }
+
+    public static void main(String[] args) {
+        int[] arr = new int[]{1, 1, 2};
+        System.out.println(removeDuplicatesInSortedArray(arr));
+        System.out.println(Arrays.toString(arr));
+
+        arr = new int[]{0, 0, 1, 1, 1, 2, 2, 3, 3, 4};
+        System.out.println(removeDuplicatesInSortedArray(arr));
+        System.out.println(Arrays.toString(arr));
+
+        arr = new int[]{0, 1, 2, 3, 4, 5};
+        System.out.println(removeDuplicatesInSortedArray(arr));
+        System.out.println(Arrays.toString(arr));
+    }
+}