#include <iostream>#include <vector>#include <algorithm>using namespace std;struct ListNode{    int val;    ListNode *next;    ListNode(int x):val(x), next(NULL){}};void printList(ListNode* head){    while(head!=NULL){        cout<<"->"<<head->val;        head = head->next;    }    cout<<endl;}ListNode *insertionSortList(ListNode *head){    if(head == NULL ||  head->next == NULL) return head;    ListNode *newHead = new ListNode(-1);    newHead->next = head;        ListNode *pre = head,*p = head->next;        while(p!=NULL){        ListNode *q = newHead;        while(q->next!=p){            if(q->next->val >= p->val ){                pre->next = p->next;                p->next = q->next;                q->next = p;                p=pre->next;                break;            }else{                q = q->next;            }                    }        if(q->next == p) {            pre = p;            p = p->next;        }    }    ListNode *res = newHead->next;    delete newHead;    return res;}int main(){    ListNode* head = new ListNode(3);    ListNode* node1 = new ListNode(2);    ListNode* node2 = new ListNode(4);    head->next = node1;    node1->next = node2;    ListNode *a = insertionSortList(head);    cout<<"ans:"<<endl;     printList(a);}