/**

 * Definition for singly-linked list.

 * struct ListNode {

 *     int val;

 *     ListNode *next;

 *     ListNode(int x) : val(x), next(NULL) {}

 * };

 */

class Solution {

public:

    ListNode* partition(ListNode* head, int x) {

        if(head == NULL) return head;

        ListNode* pres = new ListNode(-);

        pres->next = head;

        ListNode* move = pres;

        ListNode* preb = new ListNode(-);

        ListNode* move1 = preb;

        while(move->next != NULL){

            if(move->next->val < x){

                move = move->next;

            }

            else if(move->next->val >= x){

                move1->next = move->next;

                move->next = move->next->next;

                move1->next->next = NULL;

                move1 = move1->next;

            }

        }

        move->next = preb->next;

        return pres->next;

    }

};