LeetCode Partition List

Description:

Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.

You should preserve the original relative order of the nodes in each of the two partitions.
Solution:

还是两个指针，一个记录小于x，一个记录大于等于x。

import java.util.*;

public class Solution {
public ListNode partition(ListNode head, int x) {
ListNode smallerHead = null, biggerHead = null;
ListNode smallerTot = smallerHead, biggerTot = biggerHead;
ListNode temp = head, neo, next;

while (temp != null) {
next = temp.next;
temp.next = null;
if (temp.val < x) {
if (smallerHead == null) {
smallerHead = temp;
smallerTot = temp;
} else {
smallerTot.next = temp;
smallerTot = smallerTot.next;
}
} else {
if (biggerHead == null) {
biggerHead = temp;
biggerTot = temp;
} else {
biggerTot.next = temp;
biggerTot = biggerTot.next;
}
}
temp = next;
}

if (smallerHead == null)
return biggerHead;
else {
smallerTot.next = biggerHead;
return smallerHead;
}
}
}