实验内容及要求：编写程序完成一个简单职工信息系统设计。
- 编写一个建立一个输入职工信息（职工号，姓名，年龄，工资）的函数，并把职工信息存入文件“work.txt”中；写一个按照职工号查一个职工工资的函数；再写一个修改函数，实现工资小于800元的职工加90元，并把修改工资的职工信息建成一个文件“workmodify.txt”；最后写一个主函数先调用建立函数，再调用查询函数对查到的职工信息进行显示，最后调用修改函数修改职工工资。
- 要求职工信息存储在文件或结构体数组（自己选择），编写程序实现上述功能。
要求：请同学把预备知识、步骤、程序框图、调试好的程序及存在的问题写在下面（不够可以附页）。
#include <stdlib.h>
#include <stdio.h>
/** Data Type */
typedef struct employee_node {
int id;
char name[128];
int age;
double wage;
struct employee_node* next;
} *Employee;
typedef void (*Callback)(Employee);
typedef int (*Predicate)(Employee);
/** API */
Employee employee_make_node() {
Employee e;
e = (Employee)calloc(1, sizeof(struct employee_node));
if (e != NULL) {
scanf("%d%s%d%le", &e->id, e->name, &e->age, &e->wage);
}
e->next = NULL;
return e;
}
Employee employee_make_list() {
Employee e = NULL, head = NULL;
int length;
scanf("%d", &length);
while (length--) {
Employee p = employee_make_node();
if (e) {
e = e->next = p;
} else {
e = head = p;
}
}
return head;
}
Employee employee_map(Employee e, Callback fn) {
Employee p, head = e;
while (p = e) {
e = e->next;
fn(p);
}
return head;
}
Employee employee_some(Employee e, Predicate fn) {
for (; e; e = e->next) {
if (fn(e)) {
return e;
}
}
return NULL;
}
/** Interface */
/* IO */
FILE* FOUT;
void employee_output_node(Employee e) {
fprintf(FOUT, "%d %s %d %.2f\n", e->id, e->name, e->age, e->wage);
}
void employee_display_node(Employee e) {
FOUT = stdout;
if (e != NULL) {
employee_output_node(e);
}
}
void employee_display(Employee e) {
FOUT = stdout;
employee_map(e, employee_output_node);
}
void employee_save(Employee e, char* filename) {
FOUT = fopen(filename, "w");
employee_map(e, employee_output_node);
fclose(FOUT);
}
/* Search */
int search_key_id;
int employee_cmp_id(Employee e) {
return e != NULL && e->id == search_key_id;
}
Employee employee_search_by_id(Employee e) {
scanf("%d", &search_key_id);
return employee_some(e, employee_cmp_id);
}
/* Modify */
void employee_adjust_wage_node(Employee e) {
if (e != NULL && e->wage < 800) {
e->wage += 90;
}
}
void employee_adjust_wage(Employee e) {
employee_map(e, employee_adjust_wage_node);
}
/* Free */
void employee_free_node(Employee e) {
free(e);
}
Employee employee_free(Employee e) {
return employee_map(e, employee_free_node);
}
int main(void) {
Employee e = NULL;
e = employee_make_list();
employee_save(e, "work.txt");
employee_display_node(employee_search_by_id(e));
employee_adjust_wage(e);
employee_save(e, "workmodify.txt");
employee_display(e);
employee_free(e);
return EXIT_SUCCESS;
}