LintCode 链表插入排序

/**
 * Definition of ListNode
 * class ListNode {
 * public:
 *     int val;
 *     ListNode *next;
 *     ListNode(int val) {
 *         this->val = val;
 *         this->next = NULL;
 *     }
 * }
 */
class Solution {
public:
    /**
     * @param head: The first node of linked list.
     * @return: The head of linked list.
     */
    ListNode *insertionSortList(ListNode *head) {
        // write your code here
        for(ListNode *p1=head;p1!=NULL;p1=p1->next)
        {
            for(ListNode *p2=head;p2!=NULL;p2=p2->next)
            {
                int temp;
                if(p1->val < p2->val)
                {
                    temp=p1->val;
                    p1->val=p2->val;
                    p2->val=temp;
                    
                }
            }
        }
        return head;
        
    }
};