init commit

archive/algorithm/leetcode/21.c

@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct ListNode
+{
+    int val;
+    struct ListNode *next;
+};
+
+struct ListNode *mergeTwoLists(struct ListNode *l1, struct ListNode *l2)
+{
+    if (l1 == NULL)
+    {
+        return l2;
+    }
+    if (l2 == NULL)
+    {
+        return l1;
+    }
+    struct ListNode *node = l1, *node2 = l2, *prev = node;
+    while (node != NULL)
+    {
+        if (node2 != NULL && node->val > node2->val)
+        {
+            //第一个链表的值大于第二个链表的值,合并链表直到node2大于node1
+            if (prev == node)
+            {
+                //首节点
+                l1 = node2;
+                while (node2 != NULL && node2->val <= node->val)
+                {
+                    prev = node2;
+                    node2 = node2->next;
+                }
+                prev->next = node;
+            }
+            else
+            {
+                while (node2 != NULL && node2->val <= node->val)
+                {
+                    prev->next = node2;
+                    prev = node2;
+                    node2 = node2->next;
+                }
+
+                prev->next = node;
+            }
+        }
+        prev = node;
+        node = node->next;
+    }
+    if (node2 != NULL)
+    {
+        prev->next = node2;
+    }
+    return l1;
+}
+/*
+struct ListNode* mergeTwoLists(struct ListNode* l1, struct ListNode* l2) 
+{
+    struct ListNode *previous = NULL;
+    struct ListNode *t2 = l2;
+    struct ListNode *head = l1;
+
+    while (t2)
+    {
+        if (!l1 || (l1->val > t2->val))
+        {
+            l2 = l2->next;
+            t2->next = l1;
+            
+            if (previous)
+            {
+                previous->next = t2;
+            }
+            else
+            {
+                head = t2;
+            }
+            
+            t2 = l2;
+            l1 = head;
+        }
+        
+        previous = l1;
+        l1 = l1->next;
+    }
+    
+    return head;
+}
+*/
+
+int main()
+{
+    struct ListNode *node1 = malloc(sizeof(struct ListNode)), *node2 = malloc(sizeof(struct ListNode));
+    node1->val = 1;
+    node1->next = NULL;
+    node2->val = 3;
+    node2->next = NULL;
+    mergeTwoLists(node1, node2);
+    return 0;
+}