通讯录的实现
第一：实现要点
1.1 创建一个项目， 并创建相应的源代码和头文件
1.2. 定义数据结构类型到头文件：stu_info.h
1.2.1 学生结构体的成员："name", "age", "tel", "height", "weight", "addr"
1.2.2 数据结构体的成员：struct STU stu[MAX];int num; // num:用来表示有多少个记录
1.2.3 定义一个枚举变量：用来存储选项的值：enum OPTIONS { EXIT, ADD, DELETE, MODIFY, SEARCH, SHOW, ORDER }; 1.2.4 函数的声明：。。。。1.3 创建一个测试源代码文件：test.c，用于测试
里面包含一个main函数和所需要的的头文件
1.4 创建所用到的函数定义的源文件：stu_info.c
1.5 功能
（1）增、删、改、查、展示、排序（按照不同字段进行排序） （2）保存结果 （3）再次运行时，会将保存的数据读入到数据中
1.6 用到的知识难点：
（1）数据类型：结构体和枚举变量
（2）函数参数：指针变量作为函数参数
（3）指针类型：指针数组(如成员列表)
（4）函数指针数组：void (*optp[7])(struct DATA*) = { save, add, del, modify, search, show, order };
（5）回调函数：在进行排序时，如：self_qsort(data->stu, data->num, LEN, sortp[ret]);第二：各个源文件的代码清单
2.1 主函数|测试函数：test.c
#define _CRT_SECURE_NO_WARNINGS 1#pragma once#include "stu_info.h"int main(){ struct DATA data;
read_data(&data); int input; // 通过函数指针和回调函数的方式进行实现
void (*optp[7])(struct DATA*) = { save, add, del, modify, search, show, order };
do
{
menu(); scanf("%d", &input); if (-1 < input && input < 7)
{
optp[input](&data);
} else
{ printf("选择错误!\n");
}
} while (input); // 通过switch语句的方式实现
//do
//{
// menu();
// scanf("%d", &input);
// switch (input)
// {
// case ADD:
// add(&data);
// break;
// case DELETE:
// del(&data);
// break;
// case MODIFY:
// modify(&data);
// break;
// case SEARCH:
// search(&data);
// break;
// case SHOW:
// show(&data);
// break;
// case ORDER:
// order(&data);
// break;
// case EXIT:
// save(&data);
// printf("退出!");
// break;
// // break;
// default:
// printf("Select Error!");
// break;
// }
//} while (input);
return 0;
}2.2 头文件：stu_info.h
#pragma once#include <stdio.h>#include <stdlib.h>#include <string.h>#include <assert.h>#define FILENAME "datafile"#define MAX 1000#define NAME_MAX 30#define TEL_MAX 12#define ADDR_MAX 40// 定义一个枚举类型用来存储选择项enum OPTIONS { EXIT, ADD, DELETE, MODIFY, SEARCH, SHOW, ORDER };struct STU{
char name[NAME_MAX]; int age; char tel[TEL_MAX]; double height; double weight; char addr[ADDR_MAX];
};#define stu_elenum 6// char name ; int age; char tel; double height;double weight;chr addrstruct DATA{
struct STU stu[MAX];
int num;
};#define LEN sizeof(struct STU)// 函数声明// 菜单函数声明void menu();// 数据保存到磁盘文件void save(const struct DATA* data);// 读取磁盘文件中的数据保存到data结构体中void read_data(struct DATA* data);// 增加数据void add(struct DATA* data);// 展示数据void show(const struct DATA* data);// 删除数据void del(struct DATA* data);// 删除数据void modify(struct DATA* data);// 查找数据void search(const struct DATA* data);// 排序数据void order(const struct DATA* data);2.3 函数实现源文件：stu_info.c
#define _CRT_SECURE_NO_WARNINGS 1#include "stu_info.h"char* stu_elelist[] = { "name", "age", "tel", "height", "weight", "addr" };void menu(){
printf("\n\n\n");
printf("\t\t|-------------------- Student grade system --------------------|\n");
printf("\t\t| 0. exit |\n");
printf("\t\t| 1. add |\n");
printf("\t\t| 2. delete |\n");
printf("\t\t| 3. modify |\n");
printf("\t\t| 4. search |\n");
printf("\t\t| 5. show |\n");
printf("\t\t| 6. order |\n"); //printf("\t\t| 7. show |\n");
printf("\t\t|--------------------------------------------------------------|\n");
printf("\n\n\t\t\t\tplease select<0-7>:");
}void save(const struct DATA* data){ int i;
FILE* fp;
fp = fopen(FILENAME, "wb"); if (NULL == fp)
{
printf("cannot open file: %s\n", FILENAME);
exit(0);
} else
{ for (i = 0; i < data->num; i++)
{ if (fwrite(&data->stu[i], LEN, 1, fp) != 1)
{
printf("file write error!\n");
}
}
fclose(fp);
}
}void read_data(struct DATA* data){
assert(data != NULL);
FILE* fp; int i = 0;
fp = fopen(FILENAME, "rb"); if (NULL == fp)
{
printf("当前系统没有数据\n");
data->num = 0;
} else
{ //printf("%d\n", feof(fp));
data->num = 0; while (feof(fp) == 0)
{ if (fread(&data->stu[data->num], LEN, 1, fp) == 1)
{
data->num++;
}
}
fclose(fp);
}
}void show(const struct DATA* data){ int i; //char name; int age; char tel; double height; double weight; chr addr
printf("%-30s\t%-4s\t%-12s\t%-6s\t%-6s\t%-40s\n", "name", "age", "tel", "height", "weight", "addr"); for (i = 0; i < data->num; i++)
{
printf("%-30s\t%-4d\t%-12s\t%.2lf\t%.2lf\t%-40s\n",
data->stu[i].name,
data->stu[i].age,
data->stu[i].tel,
data->stu[i].height,
data->stu[i].weight,
data->stu[i].addr);
}
}static void show_by_name(const struct DATA* data, int pos){ //char name; int age; char tel; double height; double weight; chr addr
printf("%-30s\t%-4s\t%-12s\t%-6s\t%-6s\t%-40s\n", "name", "age", "tel", "height", "weight", "addr");
printf("%-30s\t%-4d\t%-12s\t%.2lf\t%.2lf\t%-40s\n",
data->stu[pos].name,
data->stu[pos].age,
data->stu[pos].tel,
data->stu[pos].height,
data->stu[pos].weight,
data->stu[pos].addr);
}// find：return pos in data->stu// not find: return -1static int find_data_by_name(const struct DATA* data, const char* name){
assert(data != NULL); int i; for (i = 0; i < data->num; i++)
{ if (strcmp(name, data->stu[i].name) == 0)
{ return i;
}
} return -1;
}static int find_name(const struct DATA* data, char* opty){ char name[NAME_MAX] = { 0 }; int pos = 0; char choose = 0; do
{
printf("please input the %s student's name:", opty);
scanf("%s", name);
pos = find_data_by_name(data, name); if (-1 == pos)
{
printf("The student of %s not in the student information system.", name);
printf("Whether continue %s student record<y/n>:", opty);
getchar();
choose = getchar();
} else
{ return pos;
}
} while (choose == 'y' || choose == 'Y'); return -1;
}int sort_stu_by_name(const void* elem1, const void* elem2){ return strcmp(((struct STU*)elem1)->name, ((struct STU*)elem2)->name);
}int sort_stu_by_age(const void* elem1, const void* elem2){ return ((struct STU*)elem1)->age - ((struct STU*)elem2)->age;
}int sort_stu_by_tel(const void* elem1, const void* elem2){ return strcmp(((struct STU*)elem1)->tel, ((struct STU*)elem2)->tel);
}int sort_stu_by_height(const void* elem1, const void* elem2){ if (((struct STU*)elem1)->height - ((struct STU*)elem2)->height > 1e-6) return 1; else if (((struct STU*)elem1)->height - ((struct STU*)elem2)->height < -1e-6)
return -1; else
return 0;
}int sort_stu_by_weight(const void* elem1, const void* elem2){ if (((struct STU*)elem1)->weight - ((struct STU*)elem2)->weight > 1e-6) return 1; else if (((struct STU*)elem1)->weight - ((struct STU*)elem2)->weight < -1e-6)
return -1; else
return 0;
}int sort_stu_by_addr(const void* elem1, const void* elem2){ return strcmp(((struct STU*)elem1)->addr, ((struct STU*)elem2)->addr);
}void self_swap(char* buf1, char* buf2, int width){ int i; char tmp; for (i = 0; i < width; i++)
{
tmp = *buf1;
*buf1 = *buf2;
*buf2 = tmp;
buf1++;
buf2++;
}
}void self_qsort(void* base, int num, int width, int (*pfunc)(const void* elem1, const void* elem2)){ int i, j; int flags; for (i = 0; i < num - 1; i++)
{
flags = 1; for (j = 0; j < num - 1 - i; j++)
{ if (pfunc((char*)base + j * width, (char*)base + (j + 1) * width) > 0)
{
flags = 0;
self_swap((char*)base + j * width, (char*)base + (j + 1) * width, width);
}
} if (1 == flags)
{ break;
}
}
}void add(struct DATA* data){ //char name; int age; char tel; double height; double weight; chr addr
char choose; char name[NAME_MAX] = { 0 }; int dup = -1; do
{ int num = data->num;
printf("input name:"); do
{
scanf("%s", name);
dup = find_data_by_name(data, name); if (-1 == dup)
{
strcpy(data->stu[num].name, name);
break;
} else
{
printf("The name of you input %s have existed, please renew input:", name);
}
} while (-1 != dup); //scanf("%s", data->stu[num].name);
printf("input age:");
scanf("%d", &data->stu[num].age);
printf("input tel:");
scanf("%s", data->stu[num].tel);
printf("input height:");
scanf("%lf", &data->stu[num].height);
printf("input weight:");
scanf("%lf", &data->stu[num].weight);
printf("input addr:");
scanf("%s", data->stu[num].addr);
data->num++;
printf("whether continue add student?<y/n>"); //scanf("%s", choose);
getchar();
choose = getchar();
} while ('y' == choose || 'Y' == choose);
}void del(struct DATA* data){ int pos = find_name(data, "delete"); int i; if (-1 != pos)
{ char* name = data->stu[pos].name;
printf("The delete student's information:\n");
show_by_name(data, pos); for (i = pos; i < data->num - 1; i++)
{
data->stu[i] = data->stu[i + 1];
}
printf("Delete Finish: %s\n", name);
data->num--;
}
}void modify(struct DATA* data){ int pos = find_name(data, "modify"); if (-1 != pos)
{
printf("The modify student's information:\n");
show_by_name(data, pos); //printf("modify name:");
//scanf("%s", data->stu[num].name);
printf("modify age:");
scanf("%d", &data->stu[pos].age);
printf("modify tel:");
scanf("%s", data->stu[pos].tel);
printf("modify height:");
scanf("%lf", &data->stu[pos].height);
printf("modify weight:");
scanf("%lf", &data->stu[pos].weight);
printf("modify addr:");
scanf("%s", data->stu[pos].addr);
printf("modify success!\n");
show_by_name(data, pos);
}
}void search(const struct DATA* data){ int pos = find_name(data, "search"); if (-1 != pos)
{
printf("search success!\n");
show_by_name(data, pos);
}
}void order(const struct DATA* data){ char choose[10]; char* info = "sort by： name | age | tel | height | weight | addr, please choose : "; int ret = -1; int i; do
{
printf("%s", info);
scanf("%s", choose); for (i = 0; i < stu_elenum; i++)
{ if (strcmp(choose, stu_elelist[i]) == 0)
{
ret = i; break;
}
}
} while (-1 == ret); int (*sortp[stu_elenum])(const void*, const void*) = { sort_stu_by_name ,sort_stu_by_age, sort_stu_by_tel, sort_stu_by_height, sort_stu_by_weight, sort_stu_by_addr };
self_qsort(data->stu, data->num, LEN, sortp[ret]);
}第三：功能展示
部分功能展示：
3.1 菜单展示：
3.2 数据展示：
3.3 修改展示：
3.4 排序展示：
