LeetCode Partition List

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.

For example,
Given 1->4->3->2->5->2 and x = 3,
return 1->2->2->4->3->5.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode partition(ListNode head, int x) {
        if (head==null) return head;
        ListNode less,greater,l,g;
        ListNode curr=head;
        less=new ListNode(-1);
        greater=new ListNode(1);
        l=less;
        g=greater;
        while (curr!=null){
            if (curr.val<x){
                less.next=curr;
                less=less.next;
            }else {
                greater.next = curr;
                greater=greater.next;
            }
            curr=curr.next;
        }
        less.next=g.next;
        greater.next=null;
        return l.next;
        
    }
}