BM5 合并k个已排序的链表

bm/src/main/java/com/huangge1199/nowcoder/bm/BM5/Solution.java

@@ -0,0 +1,38 @@
+package com.huangge1199.nowcoder.bm.BM5;
+
+import com.huangge1199.nowcoder.common.ListNode;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.PriorityQueue;
+
+/**
+ * @author hyy
+ * @Classname Solution
+ * @Description BM5 合并k个已排序的链表
+ * @Date 2022/7/26 16:32
+ */
+public class Solution {
+    public ListNode mergeKLists(ArrayList<ListNode> lists) {
+        PriorityQueue<ListNode> pq = new PriorityQueue<>(Comparator.comparingInt(o -> o.val));
+        ListNode list = new ListNode(0);
+        ListNode head = list;
+        for (ListNode tmp : lists) {
+            if (tmp != null) {
+                pq.add(tmp);
+            }
+        }
+        while (!pq.isEmpty()) {
+            head.next = pq.poll();
+            head = head.next;
+            while (head.next == null && !pq.isEmpty()) {
+                head.next = pq.poll();
+                head = head.next;
+            }
+            if (head.next != null) {
+                pq.add(head.next);
+            }
+        }
+        return list.next;
+    }
+}