C语言文件读取写入的问题

Question

我用以下代码进行读写操作一次以后，文件照常写入，可是第二次读取后就有一部分莫名消失
求大神指点

typedef struct Shu{//存储站名序号// 
    char name[10];
    int x;
    struct Shu *next;
}*S,s;
void BC2(S *head){//保存所有站点编号// 
    FILE *f;
    S p=*head;
    f=fopen("Shu.txt","w+");
    while(p!=NULL){
        fwrite(p,sizeof(s),1,f);
        p=p->next;
    }
    fclose(f);
}
struct Shu *Read2(){//读取所有站点编号// 
    FILE *f;
    S head,p;
    head=(S)malloc(sizeof(s));
    head->next=NULL;
    f=fopen("Shu.txt","r+");
    p=head;
    while(1){
        Shu* q;
        q=(S)malloc(sizeof(s));
        fread(q,sizeof(s),1,f);
        if(feof(f)){
            p->next=NULL;
            free(q);
            break;
        }
        q->next=NULL;
        p->next=q;
        p=q;
    }
    fclose(f);
    return head;
}

Answer 1

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct Shu{//存储站名序号// 
    char name[10];
    int x;
    struct Shu *next;
}*S,s;
typedef struct Zhan{
    char name[10];
    int sum;//存储到下一个站的距离// 
    int x;//标记序号// 
    struct Zhan *next;
}*Z,z;
typedef struct Lu{
    char name[10];
    struct Lu *next;
}*L,l;
bool meue3();
struct Lu *Read1();
struct Shu *Read2();
struct Zhan *Read3(char *);
void BC1(L *);
void BC2(S *);
void BC3(Z *,char *);
void Zhan_add(L *,S *);
void Zhan_xg(L *,S *);
void Zhan_shan(L *);
void put(L *,char *,Z *);
int search(S *,char *);
int main(){
     while(meue3()){
     }
     return 0;
}
int search(S *H2,char *N){//给站点编号//
    int n=0;
    S h2=*H2;
    n=h2->x;
    while(h2!=NULL){
        if(strcmp(N,h2->name)==0){
            return h2->x;
        }
        h2=h2->next;
    }
    n++;
    S h3=(S)malloc(sizeof(s));
    h3->next=NULL;
    strcpy(h3->name,N);
    h3->x=n;
    h3->next=(*H2);
    (*H2)=h3;
    return n;
}
void Zhan_add(L *H1,S *H2){
    char n[10],N[10];
    Z H3=NULL,h3;
    printf("输入要操作的公交线路\n");
    scanf("%s",N);
    put(&(*H1),N,&H3);
    if(H3!=NULL){
        h3=H3;
        while(h3->next->next!=NULL)
        h3=h3->next;//h3指向公交车倒数第二个站点// 
        Z h2=(Z)malloc(sizeof(z));
        h2->next=NULL;
        printf("\n输入要插入的站名\n");
        scanf("%s",&h2->name);
        int i; 
        h2->x=search(&(*H2),h2->name);//给站点编号// 
        h2->sum=0;
        printf("1.设置新的起点 2.设置新的终点 3.插入新站\n");
        scanf("%d",&i);
        switch(i){
            case 1:
                printf("输入%s到%s的距离\n",h2->name,H3->name);
                scanf("%d",&h2->sum);
                h2->next=H3;
                H3=h2;
                break;
            case 2:
                h3=h3->next;
                printf("输入%s到%s的距离\n",h3->name,h2->name);
                scanf("%d",&h3->sum);
                h3->next=h2;
                break;
            case 3:
                Z h4=H3;
                printf("输入要插入的位置的前面一个站点\n");
                scanf("%s",n);
                while(h4!=NULL){
                    if(strcmp(h4->name,n)==0){
                        printf("输入%s站到%s站的距离\n",h4->name,h2->name);
                        scanf("%d",&h4->sum);
                        printf("输入%s站到%s站的距离\n",h2->name,h4->next->name);
                        scanf("%d",&h2->sum);
                        h2->next=h4->next;
                        h4->next=h2;
                        break;
                    }
                    h4=h4->next;
                }
                break;
        }
        BC3(&H3,N);
        printf("成功添加站点\n");
    }
}
void Zhan_xg(L *H1,S *H2){
    char n[10],N[10];
    Z H3=NULL,h3,h4;
    printf("输入要操作的公交线路\n");
    scanf("%s",N);
    put(&(*H1),N,&H3);
    if(H3!=NULL){
        h3=H3;
        while(h3->next->next!=NULL)
        h3=h3->next;//h3指向公交车倒数第二个站点// 
        h4=H3;
        Z h2=(Z)malloc(sizeof(z));
        h2->next=NULL;
        printf("\n输入要修改的站点\n");
        scanf("%s",n);
        printf("输入新的站点名\n");
        scanf("%s",&h2->name);
        h2->sum=0;
        h2->x=search(&(*H2),h2->name);
        if(strcmp(h4->name,n)==0){//修改节点为头节点// 
            printf("输入%s站到%s站的距离\n",h2->name,h4->next->name);
            scanf("%d",&h2->sum);
            h2->next=H3->next;
            H3=h2;
        }
        else if(strcmp(h3->next->name,n)==0){//修改节点为尾节点// 
            printf("输入%s站到%s站的距离\n",h3->name,h2->name);
            scanf("%d",&h3->sum);
            h3->next=h2; 
        }
        else{
            while(h4!=NULL){
                if(strcmp(h4->next->name,n)==0){
                    printf("输入%s站到%s站的距离\n",h4->name,h2->name);
                    scanf("%d",&h4->sum);
                    printf("输入%s站到%s站的距离\n",h2->name,h4->next->next->name);
                    scanf("%d",&h2->sum);
                    h2->next=h4->next->next;
                    h4->next=h2;
                    break;
                }
                h4=h4->next;
            }
        }
        printf("成功修改站点\n");
        BC3(&H3,N);
    }
}
void Zhan_shan(L *H1){
    char n[10],N[10];
    Z H2=NULL,h3,h2;
    printf("输入要操作的公交线路\n");
    scanf("%s",N);
    put(&(*H1),N,&H2);
    if(H2!=NULL){
        h3=H2;
        while(h3->next->next!=NULL)
        h3=h3->next;//h3指向公交车倒数第二个站点// 
        printf("\n输入要删除的站点:\n");
        scanf("%s",n);
        h2=H2;
        if(strcmp(h2->name,n)==0){//删除站点为头节点//
            H2=H2->next;
        }
        else if(strcmp(h3->next->name,n)==0){//删除站点为尾节点//
            h3->next=NULL;
            h3->sum=0;
        }
        else{
            while(h2!=NULL){
                if(strcmp(h2->next->name,n)==0){
                    printf("输入%s站到%s站的距离:\n",h2->name,h2->next->next->name);
                    scanf("%d",&h2->sum);
                    h2->next=h2->next->next;
                    break;
                }
                h2=h2->next;
            }
        }
        BC3(&H2,N);
        printf("成功删除站点\n");
    }
}
bool meue3(){
    bool N=true;
    L H1;
    H1=Read1();
    H1=H1->next;
    S H2;
    H2=Read2();
    H2=H2->next;
    printf("1.站点添加  2.站点修改  3.站点删除  4.返回主页面\n");
    int n;
    scanf("%d",&n);
    switch(n){
        case 1:
            Zhan_add(&H1,&H2);
            BC2(&H2);
            break;
        case 2:
            Zhan_xg(&H1,&H2);
            BC2(&H2);
            break;
        case 3:
            Zhan_shan(&H1);
            break;
        case 4:
            N=false;
            break;
    } 
    BC1(&H1);
    return N;
}
void put(L *H1,char *N,Z *H2){
    L h1=*H1;
    while(h1!=NULL){
        if(strcmp(h1->name,N)==0)
        break;
        h1=h1->next;
    }
    if(h1==NULL)
    printf("没有找到该公交线\n");
    else{
        printf("%s公交路线如下：\n",N);
        (*H2)=Read3(N);
        (*H2)=(*H2)->next;
        Z h3=(*H2),h2=(*H2);
        printf("%s %d %d",h2->name,h2->sum,h2->x);
        h2=h2->next;
        if(h2!=NULL){
            while(h2!=NULL){//输出所有站// 
                printf("->%s %d %d",h2->name,h2->sum,h2->x);
                h2=h2->next;
            }
        }
    }
}
void BC3(Z *head,char *N){//保存公交路线的所有站点// 
    FILE *f;
    Z p=(*head);
    char F[200]="C:\\Users\\许和伟\\Desktop\\";
    strcat(F,N);
    char f1[10]=".txt";
    strcat(F,f1);
    f=fopen(F,"w+");
    while(p!=NULL){
        fwrite(p,sizeof(z),1,f);
        p=p->next;
    }
    fclose(f);
}
struct Zhan *Read3(char *N){//读取公交路线的所有站点// 
    FILE *f;
    char F[200]="C:\\Users\\许和伟\\Desktop\\";
    strcat(F,N);
    char f1[10]=".txt";
    strcat(F,f1);
    f=fopen(F,"r+");
    Z p,head;
    head=(Z)malloc(sizeof(z));
    head->next=NULL;
    p=head;
    while(1){
        Z q;
        q=(Z)malloc(sizeof(z));
        fread(q,sizeof(z),1,f);
        if(feof(f)){
            p->next=NULL;
            break;
        }
        p->next=q;
        p=q;
        p->next=NULL;
    }
    fclose(f);
    return head;
}
void BC2(S *head){//保存所有站点编号// 
    FILE *f;
    S p=*head;
    f=fopen("Shu.txt","w+");
    while(p!=NULL){
        fwrite(p,sizeof(s),1,f);
        p=p->next;
    }
    fclose(f);
}
struct Shu *Read2(){//读取所有站点编号// 
    FILE *f;
    S head,p;
    head=(S)malloc(sizeof(s));
    head->next=NULL;
    f=fopen("Shu.txt","r+");
    p=head;
    while(1){
        Shu* q;
        q=(S)malloc(sizeof(s));
        fread(q,sizeof(s),1,f);
        if(feof(f)){
            p->next=NULL;
            free(q);
            break;
        }
        q->next=NULL;
        p->next=q;
        p=q;
    }
    fclose(f);
    return head;
}
void BC1(L *head){//保存所有公交名字// 
    FILE *f;
    L p=(*head);
    f=fopen("LU.txt","w+");
    while(p!=NULL){
        fwrite(p,sizeof(l),1,f);
        p=p->next;
    }
    fclose(f);
}
struct Lu *Read1(){//读取所有公交名字//
    FILE *f;
    L head,p;
    head=(L)malloc(sizeof(l));
    head->next=NULL;
    f=fopen("LU.txt","r+");
    p=head;
    while(!feof(f)){
        L q;
        q=(L)malloc(sizeof(l));
        fread(q,sizeof(l),1,f);
        if(feof(f)){
            free(q);
            break;
        }
        p->next=q;
        p=q;
        p->next=NULL;
    }
    fclose(f);
    return head;
}