added Remove Duplicates from Sorted List (easy)

Author: minhyeong-joe

Easy/RemoveDuplicatesFromSortedList/Driver.java

@@ -0,0 +1,28 @@
+package Easy.RemoveDuplicatesFromSortedList;
+
+public class Driver {
+
+ public static void main(String[] args) {
+ Solution sol = new Solution();
+ // test case: 1 -> 1 -> 1 -> 2 -> 2 -> 3 -> 4 -> 5 -> 5
+ ListNode head = new ListNode(1, new ListNode(1, new ListNode(1, new ListNode(2, new ListNode(2, new ListNode(3, new ListNode(4, new ListNode(5, new ListNode(5)))))))));
+ System.out.print("Input: ");
+ printList(head);
+ 
+ head = sol.deleteDuplicates(head);
+ System.out.print("Output: ");
+ printList(head);
+ }
+
+ private static void printList(ListNode head) {
+ while (head != null) {
+ System.out.print(head.val);
+ if (head.next != null) {
+ System.out.print(" -> ");
+ }
+ head = head.next;
+ }
+ System.out.println();
+ }
+
+}

Easy/RemoveDuplicatesFromSortedList/README.md

@@ -0,0 +1,18 @@
+
+# Remove Duplicates from Sorted List
+[Leetcode Link](https://leetcode.com/problems/remove-duplicates-from-sorted-list/)
+
+## Problem:
+
+Given a sorted linked list, delete all duplicates such that each element appear *only once*.
+
+## Example:
+
+```
+Input: 1->1->2
+Output: 1->2
+```
+```
+Input: 1->1->2->3->3
+Output: 1->2->3
+```

Easy/RemoveDuplicatesFromSortedList/Solution.java

@@ -0,0 +1,33 @@
+package Easy.RemoveDuplicatesFromSortedList;
+
+// Definition for singly-linked list.
+class ListNode {
+ int val;
+ ListNode next;
+ ListNode() {}
+ ListNode(int val) { this.val = val; }
+ ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+}
+
+public class Solution {
+
+ public ListNode deleteDuplicates(ListNode head) {
+ if (head == null || head.next == null) {
+ return head;
+ }
+ ListNode current = head;
+ ListNode next = head.next;
+ while (next != null) {
+ if (current.val == next.val) {
+ // remove duplicate
+ current.next = next.next;
+ next = current.next;
+ } else {
+ current = current.next;
+ next = next.next;
+ }
+ }
+ return head;
+ }
+ 
+}

README.md

@@ -37,6 +37,7 @@ Languages used: Java and Python
  - [Add to Array-Form of Integer](Easy/AddToArrayFormInteger)
  - [Sqrt(x)](Easy/SqrtX)
  - [Shuffle the Array](Easy/ShuffleArray)
+ - [Remove Duplicates from Sorted List](Easy/RemoveDuplicatesFromSortedList)
 - Medium
  - [Minimum Add to Make Parentheses Valid](Medium/MinimumAddtoMakeParenthesesValid)
  - [Distribute Coins in Binary Tree](Medium/DistributionCoinsInBinaryTree)