Create main.cpp

Author: JawadSher

14 - Linked List Data Structure Problems/01 - Singly Linked List Problems/24 - Merge K Sorted Linked Lists/main.cpp

@@ -0,0 +1,41 @@
+class Solution {
+  public:
+    Node* mergeTwoLists(Node* l1, Node* l2){
+        Node* temp = new Node(0);
+        Node* current = temp;
+        
+        while(l1 != NULL && l2 != NULL){
+            if(l1 -> data < l2 -> data){
+                current -> next = l1;
+                l1 = l1 -> next;
+            }else{
+                current -> next = l2;
+                l2 = l2 -> next;
+            }
+            
+            current = current -> next;
+        }
+        
+        if(l1 != NULL) current -> next = l1;
+        if(l2 != NULL) current -> next = l2;
+        
+        return temp -> next;
+    };
+    
+    Node* mergeKListsHelper(vector<Node*>& arr, int left, int right){
+        if(left == right) return arr[left];
+        
+        int mid = left + (right - left) / 2;
+        
+        Node* leftMerge = mergeKListsHelper(arr, left, mid);
+        Node* rightMerge = mergeKListsHelper(arr, mid+1, right);
+        
+        return mergeTwoLists(leftMerge, rightMerge);
+    };
+    
+    Node* mergeKLists(vector<Node*>& arr) {
+        if(arr.empty()) return NULL;
+        
+        return mergeKListsHelper(arr, 0, arr.size() -1);
+    }
+};