solve merge k sorted list

Author: sora0319

merge-k-sorted-lists/sora0319.java

@@ -0,0 +1,26 @@
+public class Solution {
+    public ListNode mergeKLists(ListNode[] lists) {
+        PriorityQueue<ListNode> pq = new PriorityQueue<>(Comparator.comparingInt(node -> node.val));
+
+        for (ListNode list : lists) {
+            if (list != null) {
+                pq.offer(list);
+            }
+        }
+
+        ListNode temp = new ListNode(-1);
+        ListNode head = temp;
+
+        while (!pq.isEmpty()) {
+            ListNode minNode = pq.poll();
+            head.next = minNode;
+            head = head.next;
+
+            if (minNode.next != null) {
+                pq.offer(minNode.next);
+            }
+        }
+
+        return temp.next;
+    }
+}