Merge pull request #26 from atulgoel126/main-q82

Added solution for Q82 - Remove dupes from sorted list, updated README
atulgoel126 · Aug 1, 2024 · d165c25 · d165c25
2 parents 6d456fd + 16cdefa
commit d165c25
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diff --git a/README.md b/README.md
@@ -121,7 +121,7 @@ This setup provides a comprehensive structure and automation for practicing codi
 ## My Study Plan
 
 ### Heap/Priority Queue (10 Medium Questions)
-1. **Question #347 (Medium)** - Top K Frequent Elements
+1. ✅ **Question #347 (Medium)** - Top K Frequent Elements
 2. **Question #692 (Medium)** - Top K Frequent Words
 3. **Question #451 (Medium)** - Sort Characters By Frequency
 4. **Question #973 (Medium)** - K Closest Points to Origin
@@ -133,20 +133,19 @@ This setup provides a comprehensive structure and automation for practicing codi
 10. **Question #759 (Medium)** - Employee Free Time
 
 ### Sorting/Searching (5 Medium Questions)
-1. **Question #34 (Medium)** - Find First and Last Position of Element in Sorted Array
-2. **Question #347 (Medium)** - Top K Frequent Elements
-3. **Question #658 (Medium)** - Find K Closest Elements
-4. **Question #912 (Medium)** - Sort an Array
-5. **Question #162 (Medium)** - Find Peak Element
+1. ✅ **Question #34 (Medium)** - Find First and Last Position of Element in Sorted Array
+2. ✅ **Question #658 (Medium)** - Find K Closest Elements
+3. ✅ **Question #912 (Medium)** - Sort an Array
+4. ✅ **Question #162 (Medium)** - Find Peak Element
 
 ### Dijkstra's Algorithm (3 Questions)
 1. **Question #743 (Medium)** - Network Delay Time
 2. **Question #787 (Medium)** - Cheapest Flights Within K Stops
 3. **Question #1631 (Medium)** - Path With Minimum Effort
 
 ### Prim's Algorithm (2 Questions)
-1. **Question #1584 (Medium)** - Min Cost to Connect All Points
-2. **Question #1135 (Medium)** - Connecting Cities With Minimum Cost
+1. ✅ **Question #1584 (Medium)** - Min Cost to Connect All Points
+2. ✅ **Question #1135 (Medium)** - Connecting Cities With Minimum Cost
 
 ### Union Find (4 Questions)
 1. **Question #684 (Medium)** - Redundant Connection
@@ -204,7 +203,7 @@ This setup provides a comprehensive structure and automation for practicing codi
 8. **Question #152 (Medium)** - Maximum Product Subarray
 
 ### Recursion with Strings (5 Questions)
-1. **Question #22 (Medium)** - Generate Parentheses
+1. ✅ **Question #22 (Medium)** - Generate Parentheses
 2. **Question #44 (Hard)** - Wildcard Matching
 3. **Question #93 (Medium)** - Restore IP Addresses
 4. **Question #131 (Medium)** - Palindrome Partitioning
@@ -248,9 +247,9 @@ This setup provides a comprehensive structure and automation for practicing codi
 4. **Question #567 (Medium)** - Permutation in String
 
 ### Matrix (5 Questions)
-1. **Question #36 (Medium)** - Valid Sudoku
-2. **Question #54 (Medium)** - Spiral Matrix
-3. **Question #48 (Medium)** - Rotate Image
+1. ✅ **Question #36 (Medium)** - Valid Sudoku
+2. ✅ **Question #54 (Medium)** - Spiral Matrix
+3. ✅ **Question #48 (Medium)** - Rotate Image
 4. **Question #73 (Medium)** - Set Matrix Zeroes
 5. **Question #289 (Medium)** - Game of Life
 
@@ -282,13 +281,13 @@ This setup provides a comprehensive structure and automation for practicing codi
 ### Linked List (10 Questions)
 
 1. **Question #141 (Easy)** - Linked List Cycle
-2. **Question #2 (Medium)** - Add Two Numbers
+2. ✅ **Question #2 (Medium)** - Add Two Numbers
 3. **Question #21 (Easy)** - Merge Two Sorted Lists
 4. **Question #138 (Medium)** - Copy List with Random Pointer
 5. **Question #92 (Medium)** - Reverse Linked List II
 6. **Question #25 (Hard)** - Reverse Nodes in k-Group
-7. **Question #19 (Medium)** - Remove Nth Node From End of List
-8. **Question #82 (Medium)** - Remove Duplicates from Sorted List II
+7. ✅ **Question #19 (Medium)** - Remove Nth Node From End of List
+8. ✅ **Question #82 (Medium)** - Remove Duplicates from Sorted List II
 9. **Question #61 (Medium)** - Rotate List
 10. **Question #86 (Medium)** - Partition List
 
@@ -309,10 +308,10 @@ This setup provides a comprehensive structure and automation for practicing codi
 4. **Question #417 (Medium)** - Pacific Atlantic Water Flow
 
 ### Misc Questions
-1. **Question #72 (Medium)** - Edit Distance
-2. **Question #146 (Medium)** - LRU Cache
-3. **Question #200 (Medium)** - Number of Islands
-4. **Question #938 (Easy)** - Range Sum of BST
+1. ✅ **Question #72 (Medium)** - Edit Distance
+2. ✅ **Question #146 (Medium)** - LRU Cache
+3. ✅ **Question #200 (Medium)** - Number of Islands
+4. ✅ **Question #938 (Easy)** - Range Sum of BST
 
 ## Total - 145 problems
-## Completed - 7 problems
+## Completed - 18 problems
diff --git a/src/main/java/leetcode/linked_list/q82/RemoveDuplicatesfromSortedListII.java b/src/main/java/leetcode/linked_list/q82/RemoveDuplicatesfromSortedListII.java
@@ -1,6 +1,33 @@
 package leetcode.linked_list.q82;
+
+import leetcode.commons.ListNode;
+
 public class RemoveDuplicatesfromSortedListII {
-//    public ListNode deleteDuplicates(ListNode head) {
-//        return null;
-//    }
+    public ListNode deleteDuplicates(ListNode head) {
+
+        if (head == null || head.next == null) {
+            return head;
+        }
+
+        ListNode dummy = new ListNode(-1);
+        dummy.next = head;
+
+        ListNode prev = dummy;
+        ListNode curr = head;
+
+        // -1-> 1 -> 1 -> 1 -> 2 -> 3 -> 3
+        //  p                            c    c.n
+        while (curr != null && curr.next != null) {
+            if (curr.val == curr.next.val) {
+                while (curr.next != null && curr.val == curr.next.val) {
+                    curr = curr.next;
+                }
+                prev.next = curr.next;
+            } else {
+                prev = prev.next;
+            }
+            curr = curr.next;
+        }
+        return dummy.next;
+    }
 }
diff --git a/src/test/java/leetcode/linked_list/q82/RemoveDuplicatesfromSortedListIITests.java b/src/test/java/leetcode/linked_list/q82/RemoveDuplicatesfromSortedListIITests.java
@@ -1,6 +1,8 @@
+package leetcode.linked_list.q82;
+
 import static org.junit.jupiter.api.Assertions.*;
 
-import leetcode.linked_list.q82.RemoveDuplicatesfromSortedListII;
+import leetcode.commons.ListNode;
 import org.junit.jupiter.api.Test;
 
 class RemoveDuplicatesfromSortedListIITests {
@@ -68,8 +70,8 @@ void testNoDuplicateElements() {
 
     private void removeDuplicatesAndAssert(ListNode head, ListNode expected) {
         RemoveDuplicatesfromSortedListII ob = new RemoveDuplicatesfromSortedListII();
-//        ListNode actual = ob.deleteDuplicates(head);
-//        assertListNodeEquals(expected, actual);
+        ListNode actual = ob.deleteDuplicates(head);
+        assertListNodeEquals(expected, actual);
     }
 
     private void assertListNodeEquals(ListNode expected, ListNode actual) {
@@ -86,13 +88,4 @@ private void assertListNodeEquals(ListNode expected, ListNode actual) {
         assertNull(expected);
         assertNull(actual);
     }
-}
-
-class ListNode {
-    int val;
-    ListNode next;
-
-    ListNode(int val) {
-        this.val = val;
-    }
 }