↔️ Day 13

Author: AkashRajpurohit

README.md

@@ -21,6 +21,7 @@
 3. [Minimum Number of Arrows to Burst Balloons](https://leetcode.com/explore/challenge/card/october-leetcoding-challenge/560/week-2-october-8th-october-14th/3490/) ➡️ [CPP Solution](Week2/findMinArrowShots.cpp)
 4. [Remove Duplicate Letters](https://leetcode.com/explore/challenge/card/october-leetcoding-challenge/560/week-2-october-8th-october-14th/3491/) ➡️ [CPP Solution](Week2/removeDuplicateLetters.cpp)
 5. [Buddy Strings](https://leetcode.com/explore/challenge/card/october-leetcoding-challenge/560/week-2-october-8th-october-14th/3492/) ➡️ [CPP Solution](Week2/buddyStrings.cpp)
+6. [Sort List](https://leetcode.com/explore/challenge/card/october-leetcoding-challenge/560/week-2-october-8th-october-14th/3493/) ➡️ [CPP Solution](Week2/sortList.cpp)
 
 ## Week 3 🚧
 

Week2/sortList.cpp

@@ -0,0 +1,59 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode() : val(0), next(nullptr) {}
+ *     ListNode(int x) : val(x), next(nullptr) {}
+ *     ListNode(int x, ListNode *next) : val(x), next(next) {}
+ * };
+ */
+class Solution {
+private:
+    ListNode* findMiddleNode(ListNode* head) {
+        ListNode* slow = head;
+        ListNode* fast = head->next;
+        
+        while(fast != NULL && fast->next != NULL) {
+            fast = fast->next->next;
+            slow = slow->next;
+        }
+        ListNode* mid = slow->next;
+        slow->next = NULL;
+        
+        return mid;
+    }
+    
+    ListNode* mergeList(ListNode* l1, ListNode* l2) {
+        ListNode* dummyHead = new ListNode(-1);
+        ListNode* current = dummyHead;
+        
+        while(l1 != NULL && l2 != NULL) {
+            if(l1->val <= l2->val) {
+                current->next = l1;
+                l1 = l1->next;
+            } else {
+                current->next = l2;
+                l2 = l2->next;
+            }
+            
+            current = current->next;
+        }
+        
+        current->next = l1 != NULL ? l1 : l2;
+        
+        return dummyHead->next;
+    }
+public:
+    ListNode* sortList(ListNode* head) {
+        if(head == NULL || head->next == NULL)
+            return head;
+        
+        ListNode* middle = findMiddleNode(head);
+        
+        ListNode* left = sortList(head);
+        ListNode* right = sortList(middle);
+        
+        return mergeList(left, right);
+    }
+};