LeeCode 148 Sort List

题目

分析

全部取出来放入vector中进行排序再构造一条新链表

题解

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* sortList(ListNode* head) {
        vector<int> ans;
        if(head == NULL)
            return NULL;
        while(head != NULL){
            ans.push_back(head->val);
            head = head->next;
        }
        sort(ans.begin(),ans.end());
        ListNode newhead(0);
        ListNode *temphead = &newhead;
        ListNode *p = &newhead;
        for(int i=0;i<ans.size();i++){
            ListNode *temp = new ListNode(ans[i]);
            temphead->next = temp;
            temphead = temphead->next;
        }
        p = p->next;
        return p;
    }
};