2024/8/26 LeetCode Hot100 LinkedList

src/main/java/com/cool/hot100/linkedlist/Num23.java

@@ -0,0 +1,54 @@
+package com.cool.hot100.linkedlist;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/26/23:12
+ * DayNumber 2
+ * Hard 3
+ */
+public class Num23 {
+
+
+    public ListNode mergeKLists(ListNode[] lists) {
+        if (lists.length == 0) return null;
+        List<ListNode> list = Arrays.stream(lists).collect(Collectors.toList());
+        while (list.size() > 1) {
+            for (int i = list.size() - 1; i > 0; i -= 2) {
+
+                ListNode listNode = list.get(i);
+                ListNode listNode1 = list.get(i - 1);
+                ListNode newListNode = merge(listNode1, listNode);
+                list.remove(i);
+                list.remove(i-1);
+                list.add(newListNode);
+
+            }
+        }
+        return list.get(0);
+    }
+
+    public ListNode merge(ListNode node1, ListNode node2) {
+        ListNode head = new ListNode(0);
+        ListNode node = head;
+        while (node1 != null && node2 != null) {
+            if (node1.val <= node2.val) {
+                node.next = node1;
+                node1 = node1.next;
+            } else {
+                node.next = node2;
+                node2 = node2.next;
+            }
+            node = node.next;
+        }
+        node.next = node1 == null ? node2 : node1;
+        return head.next;
+    }
+
+}