[LeetCode] Insertion Sort List

/**
* Definition for singly-linked list.
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *insertionSortList(ListNode *head) {
if (!head){return NULL;}
ListNode *p=new ListNode(0);
p->next = head;
head = p;
ListNode *q;

while (p->next!=NULL){
q = head;
bool flag = false;
while (q!=p){
if (q->next->val>p->next->val){
ListNode* tmp1=p->next;
p->next =p->next->next;
tmp1->next = q->next;
q->next = tmp1;
flag =true;
break;
}else{
q=q->next;
}
}
if (!flag){
p=p->next;
}
}
return head->next;
}

};