利用c语言制作二级菜单，一直报错，很无奈

Question

#include
#include
void nemu1();
void nemu2();
int main()
{ int x;
while(1);
{system("cls");
printf("\n\n\n\n\n\n\n\n");
printf("\t\t\t\t\t1:顺序表\n");
printf("\t\t\t\t\t2:链表\n");
printf("\t\t\t\t\t3:退出\n");
printf("\n\t\t\t\t\t请输入您的选择（1-3）=：");
scanf("%d",&x);
}
switch(x)
{case 1:nemu1(); break;
case 2:nemu2(); break;
default:printf("error"); break;}
return 1;
}

void menu1();
{int y;
while(1)
{system("cls");
printf("\n\n\n\n\n\n\n\n");

printf("\t\t\t\t\t1:创建顺序线性表\n");
printf("\t\t\t\t\t2:求顺序线性表的长度\n");
printf("\t\t\t\t\t3:按序号取顺序表元素\n");
printf("\t\t\t\t\t4:按值查找顺序表\n");
printf("\t\t\t\t\t5:插入元素\n");
printf("\t\t\t\t\t6:删除元素\n");
printf("\t\t\t\t\t7:输出顺序线性表\n");
printf("\t\t\t\t\t8:返回\n");
printf("\t\t\t\t\t\t请输入您的选择（1-8）=:");
scanf("%d",&y);}
if(y==8) break;
switch(y)
{ case 1:printf("这里是创建顺序线性表"); break;
case 2:printf("这里是求顺序线性表的长度");break;
case 3:printf("这里是按序号取顺序表元素"); break;
case 4:printf("这里是按值查找顺序表"); break;
case 5:printf("这里是插入元素"); break;
case 6:printf("这里是删除元素"); break;
case 7:printf("这里是输出顺序线性表"): break;
default:printf("error"); break;}
return 1;
}

void menu2();
{int z;
while(1)
{system("cls");
printf("\n\n\n\n\n\n\n\n");
printf("\t\t\t\t\t1:创建链式线性表\n");
printf("\t\t\t\t\t2:求链式线性表的长度\n");
printf("\t\t\t\t\t3:按序号取链表元素\n");
printf("\t\t\t\t\t4:按序号取链表元素\n");
printf("\t\t\t\t\t5:插入元素\n");
printf("\t\t\t\t\t6:删除元素\n");
printf("\t\t\t\t\t7:输出链式线性表\n");
printf("\t\t\t\t\t8:返回\n");
printf("\t\t\t\t\t\t请输入您的选择（1-8）=:");
scanf("%d",&z);}
if(z==8) break;
switch(x)
{ case 1:printf("这里是创建链式线性表"); break;
case 2:printf("这里是求链式线性表的长度"); break;
case 3:printf("这里是按序号取链表元素"); break;
case 4:printf("这里是按序号取链表元素"); break;
case 5:printf("这里是插入元素"); break;
case 6:printf("这里是删除元素"); break;
case 7:printf("这里是输出链式线性表");break;
default:printf("error"); break;}
return 1;
}

Answer 1

#include <bits/stdc++.h>
int menu1();
int menu2();
int main() {
    int x;
    while(1) {
        system("cls");
        printf("\n\n\n\n\n\n\n\n");
        printf("\t\t\t\t\t1:顺序表\n");
        printf("\t\t\t\t\t2:链表\n");
        printf("\t\t\t\t\t3:退出\n");
        printf("\n\t\t\t\t\t请输入您的选择（1-3）=：");
        scanf("%d",&x);
        switch(x)
        {
            case 1:menu1(); break;
            case 2:menu2(); break;
            case 3:return 0;break;
            default:printf("error");return 1; break;
        }
        printf("\n");
        system("pause");
    }
    return 0;
}

int menu1() {
    int y;
    while(1) {
        system("cls");
        printf("\n\n\n\n\n\n\n\n");

        printf("\t\t\t\t\t1:创建顺序线性表\n");
        printf("\t\t\t\t\t2:求顺序线性表的长度\n");
        printf("\t\t\t\t\t3:按序号取顺序表元素\n");
        printf("\t\t\t\t\t4:按值查找顺序表\n");
        printf("\t\t\t\t\t5:插入元素\n");
        printf("\t\t\t\t\t6:删除元素\n");
        printf("\t\t\t\t\t7:输出顺序线性表\n");
        printf("\t\t\t\t\t8:返回\n");
        printf("\t\t\t\t\t\t请输入您的选择（1-8）=:");
        scanf("%d",&y);
        if(y==8) break;
        switch(y) { 
            case 1:printf("这里是创建顺序线性表"); break;
            case 2:printf("这里是求顺序线性表的长度");break;
            case 3:printf("这里是按序号取顺序表元素"); break;
            case 4:printf("这里是按值查找顺序表"); break;
            case 5:printf("这里是插入元素"); break;
            case 6:printf("这里是删除元素"); break;
            case 7:printf("这里是输出顺序线性表"); break;
            default:printf("error"); break;
        }
        printf("\n");
        system("pause");
    }
    return 1;
}

int menu2(){
int z;
while(1)
{
system("cls");
printf("\n\n\n\n\n\n\n\n");
printf("\t\t\t\t\t1:创建链式线性表\n");
printf("\t\t\t\t\t2:求链式线性表的长度\n");
printf("\t\t\t\t\t3:按序号取链表元素\n");
printf("\t\t\t\t\t4:按序号取链表元素\n");
printf("\t\t\t\t\t5:插入元素\n");
printf("\t\t\t\t\t6:删除元素\n");
printf("\t\t\t\t\t7:输出链式线性表\n");
printf("\t\t\t\t\t8:返回\n");
printf("\t\t\t\t\t\t请输入您的选择（1-8）=:");
scanf("%d",&z);
if(z==8) break;
switch(z)
{ case 1:printf("这里是创建链式线性表"); break;
case 2:printf("这里是求链式线性表的长度"); break;
case 3:printf("这里是按序号取链表元素"); break;
case 4:printf("这里是按序号取链表元素"); break;
case 5:printf("这里是插入元素"); break;
case 6:printf("这里是删除元素"); break;
case 7:printf("这里是输出链式线性表");break;
default:printf("error"); break;}
        printf("\n");
        system("pause");
return 1;
}
}

我帮你改过，测试过了，没有问题，麻烦采纳，谢谢！