Create 21. Merge Two Sorted Lists.cpp

Author: ZengruiWang

21. Merge Two Sorted Lists.cpp

@@ -0,0 +1,29 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode(int x) : val(x), next(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {
+        ListNode* dummy = new ListNode(0), *cur = dummy;
+        int val_1, val_2;
+        while(l1 || l2){
+            val_1 = l1 ? l1->val : INT_MAX;
+            val_2 = l2 ? l2->val : INT_MAX;
+            if(val_1 < val_2){
+                cur->next = l1;
+                l1 = l1 ? l1->next : NULL;
+            }else{
+                cur->next = l2;
+                l2 = l2 ? l2->next : NULL;
+            }
+            cur = cur->next;
+        }
+        return dummy->next;
+        
+    }
+};