关于#C++#的问题，请各位专家解答，绘制一下流程图，顺便再看看帮我改改。

#include<iostream>
#include<cstdlib>
using namespace std;
#define Elemtype int
typedef struct node {
    struct node* next;
    Elemtype data;
}node,*NL;//结构
NL init()
{
    NL head = new node;
    head->next = NULL;
    return head;
}//初始化，分配一个节点作为链表头//初始化，分配一个节点作为链表头
int PUSH(NL n)//打印列表函数
{

    if (!n)
    {
        printf("empty error\n");
        return 0;
    }
    while (n->next)
    {
        n = n->next;
    }
    cout<<"\t\t\t\t\t输入添加的节点数值: ";
    int data;
    cin >> data;
    NL nc = new node;
    nc->next = NULL;
    n->next = nc;
    nc->data = data;
    printf("\t\t\t\t添加成功\n");
}//天加节点的函数

int show_list(NL n)
{
    if (!n || !(n->next))
    {
        printf("empty error\n");
        return 0;
    }
    cout<<"\n\n\n\t\t\t\t\t";
    while (n->next)
    {
        cout << n->next->data << "->";
        n = n->next;
    }
    cout<<"空\n";
    return 0;
}
int search_number(NL n)//搜索节点函数
{
    bool found = false;
    if (!n || !(n->next))
    {
        cout<<"empty error\n";
        return 0;
    }
    cout<<"\t\t\t\t\t输入查询节点的值: ";
    int data;
    cin >> data;
    int index = 0;
    while (n->next)
    {
        if (n->next->data == data) {
            cout << "\t\t\t\t\t" << data << "在第" << index << "位" << endl;;
            found = true;
        }
        index++;
        n = n->next;
    }
    if (!found)
        cout<<"\t\t\t\t\t"<<data<<"不在名单上\n";
    return 0;
}
int sort_list(NL n)
{
    if (!n)
    {
        cout<<"empty error\n";
        return 0;
    }
    NL ni = n;
    NL na = n;
    while (ni->next)
    {
        na = ni->next;
        while (na->next)
        {
            if (ni->next->data > na->next->data)
                ni->next->data ^= na->next->data ^= ni->next->data ^= na->next->data;
            na = na->next;
        }
        ni = ni->next;
    }
    cout<<"\t\t\t\t\t排序成功\n";
}//排序函数
int delete_duplicate(NL n)
{
    if (!n)
    {
        cout<<"empty error\n";
        return 0;
    }
    while (n->next)
    {
        NL np = n->next;
        while(np->next)
        {
            if (np->next->data == n->next->data)
            {
                NL ptr = np->next;
                np->next = np->next->next;//从头节点的next开始遍历，如果后面有节点相同则释放
                free(ptr);
            }
            np = np->next;
        }
        n = n->next;
    }
    return 0;
}//删除重复值函数
int delete_list(NL n)
{
    while (n)
    {
        NL ptr = n;
        n = n->next;
        free(ptr);//根据链表特性不断释放空间
    }
    return 0;
}//删除链表函数
int menu()
{
    int length;//定义初始时的链表长度
    NL n = init();
    cout<<"\n\n\n\t\t\t\t\t请输入一个数字: ";
    cin >> length;
    for (int i = 0; i < length; i++)
    {
        PUSH(n);//不断添加节点
    }
    while (1)
    {
        system("cls");//进入菜单
        back://如果下面输出错误回到此处
        cout<<"\n\n\n\t\t\t\t\t███████████████████████████████\n";
        cout<<"\t\t\t\t\t█                             █\n";
        cout<<"\t\t\t\t\t█         1) 添加数字         █\n";
        cout<<"\t\t\t\t\t█         2) 显示列表         █\n";
        cout<<"\t\t\t\t\t█         3) 搜索数字         █\n";
        cout<<"\t\t\t\t\t█         4) 列表排序         █\n";
        cout<<"\t\t\t\t\t█         5) 删除重复         █\n";
        cout<<"\t\t\t\t\t█         6) 删除列表         █\n";
        cout<<"\t\t\t\t\t█         0) 退出系统         █\n";
        cout<<"\t\t\t\t\t█                             █\n";
        cout<<"\t\t\t\t\t██████████████████████████████\n";//菜单
        cout<<"\n\t\t\t\t\t你的选择> ";
        int choice;
        cin >> choice;
        switch (choice)
        {
        case 1:
            PUSH(n);
            break;
        case 2:
            show_list(n);
            break;
        case 3:
            search_number(n);
            break;
        case 4:
            sort_list(n);
            break;
        case 5:
            delete_duplicate(n);
            break;
        case 6:
            delete_list(n);
            n = NULL;
            break;
        case 0:
            exit(0);
        default:
            system("cls");
            cout<<"\t\t\t\t\t输入错误请重新输入..";//输入错误回到back标签处
            goto back;
        }
        cout<<"\t\t\t\t\t输入回车返回菜单\n";//等待回车，避免system("cls")将查询的信息清楚过快，使得人眼看不到
        char wait = getchar();
        wait = getchar();
    }

}//菜单
int main(void)
{
    menu();
    return 0;
}