leetcode86

對不起我厚顏無恥

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    void insert(ListNode * p,ListNode * start,int x)
    {
        ListNode* p1 = start;
        ListNode* p2 = start->next;
        while(p2)
        {
            if(p2->val >= x) break;
            else
            {
                p1 = p2;
                p2 = p2->next;
            }
        }
        p1->next = p;
        p->next = p2;
    }
    
    ListNode* partition(ListNode* head, int x) {
        ListNode* start = new ListNode(INT_MIN);
        start->next = head;
        ListNode * p1 = start;
        ListNode * p2 = head;
        ListNode * p3 = NULL;
        vector<ListNode*>v;
        
        while(p2)
        {
            p3 = (p2 == NULL) ? NULL : p2->next;
            if(p2->val < x)
            {
                p1->next = p3;
                v.push_back(p2);
                p2 = p3;
            }
            else
            {
                p1 = p2;
                p2 = p2->next;
            }
        }
        
        for(int i = 0;i<v.size();i++)
        {
            insert(v[i],start,x);
        }
        return start->next;
    }
};