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MergeK.java
74 lines (54 loc) · 1.23 KB
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MergeK.java
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import java.util.*;
public class MergeK{
public static ListNode mergeKlists(List<ListNode> lists){
if(lists.size()== 0)
return null;
PriorityQueue <ListNode> p = new PriorityQueue<ListNode>(lists.size(),
new Comparator<ListNode>(){
@Override
public int compare(ListNode a, ListNode b){
return a.val - b.val;
}
});
for(ListNode list: lists){
if(list != null)
p.add(list);
}
ListNode head = new ListNode(0);
ListNode result = head;
while(p.size() > 0){
ListNode temp = p.poll();
result.next = temp;
if(temp.next!=null){
p.add(temp.next);
}
result = result.next;
}
return head.next;
}
public static void main(String[] args){
ListNode l1 = new ListNode(2);
l1.next = new ListNode(4);
ListNode l2 = new ListNode(1);
l2.next = new ListNode(3);
ListNode l3 = new ListNode(3);
l3.next = new ListNode(9);
List<ListNode> list = new LinkedList<ListNode>();
list.add(l1);
list.add(l2);
list.add(l3);
ListNode result = mergeKlists(list);
while(result.next!=null){
System.out.println(result.val);
result = result.next;
}
}
}
class ListNode {
int val;
ListNode next;
ListNode(int x) {
val = x;
next = null;
}
}