C语言问题求代码高手来解决啊

Question

建立一个动态连接表 连表中的每一结点包括
学号 姓名 性别 年龄 成绩。 程序能实现以下功能： 1建立链表 显示链表 查找链表中是否存在某个元素，并显示这个元素的所有信息，若没有这个元素则显示“无此记录”的信息 4删除链表中指定的学号的结点 5 在链表中指定的位置插入一个新结点
要求 陈滚运行中显示实现以上功能锁构成的菜单，然后根据选项调用相应程序及对影的结果然后在现实菜单结构 知道按’退出‘选项程序执行结束

Answer 1

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

struct student{
int id;
char name[30];
char gender;
int age;
float score;
struct student *next;
};

typedef struct student Student;

Student *s=0;

void add(int id,char name[],char gender,int age,float score){
if(s==0){
s=(Student *)malloc(sizeof(Student));
s->id=id;
strcpy(s->name,name);
s->gender=gender;
s->age=age;
s->score=score;
s->next=0;
}
else{
Student *p=s;
while(p->next!=0){
p=p->next;
}
Student *t=(Student *)malloc(sizeof(Student));
t->id=id;
strcpy(t->name,name);
t->gender=gender;
t->age=age;
t->score=score;
t->next=0;
p->next=t;
}
}

void display(){
Student *p=s;
while(p!=0){
printf("%5d %s %c %5d %5.2f\n",p->id,p->name,p->gender,p->age,p->score);
p=p->next;
}
}

void search(int id){
Student *p=s;
while(p!=0){
if((p->id)==id) {printf("%5d %s %c %5d %5.2f\n",p->id,p->name,p->gender,p->age,p->score);return;}
else p=p->next;
}
printf("No such record.\n");
}

Student *del(int id){
Student *p1=s;
Student *p2=p1;
if(s->id==id){s=s->next;free(p1);return s;}
else{
while(p1!=0){
p2=p1;
p1=p1->next;
if(p1->id==id){
p2->next=p1->next;
free(p1);
return s;
}
}
return s;
}
}

Student *insert(Student *n,int index){
if(index<0) return 0;
else if(index==0) {n->next=s;return n;}
else{
Student *p2=s;
while(index>1){
p2=p2->next;
index--;
}
n->next=p2->next;
p2->next=n;
return s;
}
}

int main(){
int i;
do{
printf("Enter the function you want:\n");
printf("1. Add 2.Insert 3.Delete 4.Search 5.Display 6.Quit\n");
scanf("%d",&i);
if(i==1){
int id;
printf("Enter the id: ");
scanf("%d",&id);
char name[30];
printf("Enter the name: ");
scanf("%s",name);
char gender;
printf("Enter the gender: ");
scanf("%c",&gender);
int age;
printf("Enter the age: ");
scanf("%d",&age);
float score;
printf("Enter the score: ");
scanf("%f",&score);
add(id,name,gender,age,score);
}
else if(i==2){
Student *n=(Student *)malloc(sizeof(Student));
printf("Enter the id: ");
scanf("%d",&(n->id));
printf("Enter the name: ");
scanf("%s",n->name);
printf("Enter the gender: ");
scanf("%c",&(n->gender));
printf("Enter the age: ");
scanf("%d",&(n->age));
printf("Enter the score: ");
scanf("%f",&(n->score));
n->next=0;
int index;
printf("Enter the index: ");
scanf("%d",&index);
s=insert(n,index);
}
else if(i==3){
int id;
printf("Enter the id: ");
scanf("%d",&id);
s=del(id);
}
else if(i==4){
int id;
printf("Enter the id: ");
scanf("%d",&id);
search(id);
}
else if(i==5){
display();
}
else if(i==6){
Student *p;
while(s!=0){
p=s->next;
free(s);
s=p;
}
break;
}
}while(1);
return 0;
}