c语言课程设计_简单通讯录系统

/*简单通讯录*/
#include <stdio.h>
#include <stdlib.h>
struct address{
  char name[20];
  char street[20];
  char city[10];
  char state[10];
  char zip[7];
  struct address *next;
  struct address *prior;
  }list_entry;

struct address *start;
struct address *last;

void enter();
void display();
void search();
void save();
void load();
void list();

struct address *find(char *name);
struct address *dls_store(struct address *,struct address *);

main()
{
clrscr();
start=last=NULL;
load();
for (;;){
  switch(menu_select()){
    case 1:enter();break;
    case 2:delete();break;
    case 3:list();break;
    case 4:search();break;
    case 5:save();break;
    case 6:exit(0);
    }
  }
}

menu_select()
{
char c;
printf("1.Enter\n");
printf("2.Delete\n");
printf("3.List\n");
printf("4.Search\n");
printf("5.Save\n");
printf("6.Quit\n");
do{
  printf("\nEnter you choice:");
  c=getche();
  }while (c<'0'||c>'6');
return c-48;
}

void enter()
{
struct address *info;
for (;;){
  info=(struct address *)malloc(sizeof(list_entry));
  if (!info){
    printf("\nout of memory");
  return;
  }
  inputs("\nenter name:",info->name,19);
  if (!info->name[0]) break;
  inputs("enter street:",info->street,19);
  inputs("enter city:",info->city,9);
  inputs("enter state:",info->state,9);
  inputs("enter zip:",info->zip,6);
  start=dls_store(info,start);
  }
}

inputs(char *prompt,char *s,int count)
{
char p[255];
do{
  printf(prompt);
  gets(p);
  if (strlen(p)>count) printf("\ntoo long\n");
  }while (strlen(p)>count);
  strcpy(s,p);
}

struct address *dls_store(struct address *i,struct address *top)
{
struct address *old,*p;
if (last==NULL){
  i->next=NULL;
  i->prior=NULL;
  last=i;
  return i;
  }
p=top;
old=NULL;
while(p){
  if (strcmp(p->name,i->name)<0){
    old=p;p=p->next;
    }
  else{
    if(p->prior){
      p->prior->next=i;
      i->next=p;
      i->prior=p->prior;
      p->prior=i;
      return top;
      }
    i->next=p;
    i->prior=NULL;
    p->prior=i;
    return i;
    }
  }
  old->next=i;
  i->next=NULL;
  i->prior=old;
  last=i;
  return start;
}

delete()
{
struct address *info;
char s[80];
printf("enter name:");
gets(s);
info=find(s);
if (info) {
  if (start==info){
    start=info->next;
    if (start)
      start->prior=NULL;
    else
      last=NULL;
    }
  else{
    info->prior->next=info->next