[LeetCode 第6题] -- Insertion Sort List

题目链接: Insertion Sort List

题目意思: 利用插入排序，对链表排序

代码:

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    void sort (vector<ListNode*> &arrList, int size);
    ListNode *insertionSortList(ListNode *head);
};

void Solution::sort (vector<ListNode*> &arrList, int size) {
    for (int i = 1; i < size; i++) {
        int j = i-1;
        int tmp = arrList[i]->val;
        for (j = i-1; j >= 0; j--) {
            if (tmp >= arrList[j]->val) {
               break;
            }
            arrList[j+1]->val = arrList[j]->val;
        }
        if (j < (i-1)) {
            arrList[j+1]->val = tmp;
        }
     }
}

ListNode* Solution::insertionSortList(ListNode *head) {
     if (NULL == head) {
     	 return NULL;
     }
     int size = 0;
     ListNode *tmpHead = head;
     while (tmpHead != NULL) {
         size++;
         tmpHead = tmpHead->next;
     }
     vector<ListNode*> arrList;
     tmpHead = head;
     while (tmpHead != NULL) {
         arrList.push_back(tmpHead);
         tmpHead = tmpHead->next;
     }
     sort(arrList, size);
     return head;
}