partition-list.js

// 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.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} x
 * @return {ListNode}
 */
var partition = function(head, x) {
    var less = new ListNode(-1);
    var more = new ListNode(-1);
    var temp1 = less;
    var temp2 = more;
    while (head) {
        if (head.val < x) {
            less.next = head;
            less = less.next;
        } else {
            more.next = head;
            more = more.next;
        }
        head = head.next;
    }
    more.next = null;
    less.next = temp2.next;
    return temp1.next;
};