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Author: kedebug

MergeTwoSortedLists/MergeTwoSortedLists.cpp

@@ -0,0 +1,43 @@
+/**
+ * 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) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        ListNode prev_head(0);
+        ListNode *sorted_list = &prev_head;
+        
+        while (l1 && l2) {
+            if (l1->val < l2->val) {
+                sorted_list->next = l1;
+                l1 = l1->next;
+                sorted_list = sorted_list->next;
+            }
+            else {
+                sorted_list->next = l2;
+                l2 = l2->next;
+                sorted_list = sorted_list->next;
+            }
+        }
+        
+        while (l1) {
+            sorted_list->next = l1;
+            l1 = l1->next;
+            sorted_list = sorted_list->next;
+        }
+        while (l2) {
+            sorted_list->next = l2;
+            l2 = l2->next;
+            sorted_list = sorted_list->next;
+        }
+        return prev_head.next;
+    }
+};