Merge Two Sorted Lists

Merge Two Sorted Lists.cpp

@@ -0,0 +1,38 @@
+/**
+ * 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 {
+public:
+    ListNode* mergeTwoLists(ListNode* list1, ListNode* list2) {
+        ListNode* t1 = list1;
+        ListNode* t2 = list2;
+        ListNode* dummyNode = new ListNode(-1);
+        ListNode* temp = dummyNode;
+
+        while(t1 != NULL && t2 != NULL){
+            if(t1 -> val < t2 -> val){
+                temp->next = t1;
+                temp = t1;
+                t1 = t1->next;
+            }
+            else{
+                temp->next = t2;
+                temp = t2;
+                t2 = t2->next;
+
+            }
+        }
+        if(t1) temp->next =t1;
+        else{
+            temp->next = t2;
+        }
+        return dummyNode->next;
+    }
+};