我用system函数换成白底蓝字了

#define _CRT_SECURE_NO_WARNINGS
#define BOOK_NAME 32
#define LIBRARY_SIZE 16
#define ID_SIZE 12
#define KEY_SIZE 12
#define STUDENTS_NUMBER 16
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct book {char book_name[BOOK_NAME];int book_quantity;struct book(){int i;for (i = 0; i < BOOK_NAME; i++) {book_name[i] = '\0';}book_quantity = 0;}
}Book;
typedef struct library {Book Books[LIBRARY_SIZE];void check_books(){char null_str[BOOK_NAME] = { '\0' };int i;printf("展示馆内图书:\n");for (i = 0; i < LIBRARY_SIZE; i++) {if (strcmp(Books[i].book_name, null_str) != 0) {printf("%s 剩余%d本\n",Books[i].book_name,Books[i].book_quantity);}}}
}Library;
typedef struct student {char name[8];char major;int current_number;int max_number;char Id_number[ID_SIZE];char Key[KEY_SIZE];Book Borrow[2];struct student(){int i;for (i = 0; i < ID_SIZE; i++) {Id_number[i] = '\0';}for (i = 0; i < KEY_SIZE; i++) {Key[i] = '\0';}}void manage_students(){current_number = 0;if (major == 'A') {max_number = 2;}else if (major == 'B') {max_number = 1;}}
}Student;
typedef struct students {Student Students[STUDENTS_NUMBER];
}StudentsData;
void Initial_Students(StudentsData &STU)                     ////////此处曾出现“表达式的左端必须是可修改的值”
{int i = 0;strcpy(STU.Students[0].Id_number, "2019112330");strcpy(STU.Students[0].Key, "2330");STU.Students[0].major = 'A';STU.Students[0].manage_students();strcpy(STU.Students[1].Id_number, "2019112331");strcpy(STU.Students[1].Key, "2331");STU.Students[1].major = 'A';STU.Students[1].manage_students();strcpy(STU.Students[2].Id_number, "2019112332");strcpy(STU.Students[2].Key, "2332");STU.Students[2].major = 'A';STU.Students[2].manage_students();strcpy(STU.Students[3].Id_number, "2019112333");strcpy(STU.Students[3].Key, "2333");STU.Students[3].major = 'A';STU.Students[3].manage_students();strcpy(STU.Students[4].Id_number, "2019112334");strcpy(STU.Students[4].Key, "2334");STU.Students[4].major = 'A';STU.Students[4].manage_students();strcpy(STU.Students[5].Id_number, "2019112335");strcpy(STU.Students[5].Key, "2335");STU.Students[5].major = 'A';STU.Students[5].manage_students();
}
void Initial_Library(Library &L)
{strcpy(L.Books[0].book_name, "C语言程序设计");L.Books[0].book_quantity = 1;strcpy(L.Books[1].book_name, "马克思主义原理");L.Books[1].book_quantity = 1;strcpy(L.Books[2].book_name, "高等数学");L.Books[2].book_quantity = 1;strcpy(L.Books[3].book_name, "普通地质学");L.Books[3].book_quantity = 1;strcpy(L.Books[4].book_name, "大学化学");L.Books[4].book_quantity = 1;
}
int login_check(StudentsData& STU, char id[], char k[])
{int i, flag = -1;for (i = 0; i < STUDENTS_NUMBER; i++) {if (strcmp(STU.Students[i].Id_number, id) == 0) {if (strcmp(STU.Students[i].Key, k) == 0) {flag = i;break;}}}return flag;
}
int Login(StudentsData &STU)
{int log;char temp_id[ID_SIZE] = { '\0' };char temp_key[KEY_SIZE] = { '\0' };start_login:printf("----图书管理系统----\n");printf("------登录界面------\n");printf("用户: ");scanf("%s", temp_id);printf("密码: ");scanf("%s", temp_key);log = login_check(STU, temp_id, temp_key);if (log == -1) {printf("用户名或密码有错，请重新输入\n");system("pause");system("cls");goto start_login;}return log;
}
int Display_Student(StudentsData &STU, int flag)
{int remain;remain = STU.Students[flag].max_number - STU.Students[flag].current_number;printf("用户%s当前已借%d本，还可借%d本\n", STU.Students[flag].Id_number, STU.Students[flag].current_number, remain);return remain;
}
void Borrow_Book(Library& L, StudentsData& STU, int stu)
{int i, bk = -1, retry;char temp[BOOK_NAME] = { '\0' };do {L.check_books();system("pause"); system("cls");printf("请输入需要借阅的书: ");scanf("%s", temp);for (i = 0; i < LIBRARY_SIZE; i++) {if (strcmp(temp, L.Books[i].book_name) == 0) {bk = i;break;}}if (bk != -1) {if (L.Books[bk].book_quantity == 0) {printf("此书已被借完\n是否重新选择？是...1否...0\n");scanf("%d", &retry);system("pause"); system("cls");continue;}else if (L.Books[bk].book_quantity > 0) {strcpy(STU.Students[stu].Borrow[0].book_name, L.Books[bk].book_name);STU.Students[stu].current_number++;if (STU.Students[stu].current_number < STU.Students[stu].max_number) {L.Books[bk].book_quantity--;printf("借阅一本%s\n",L.Books[bk].book_name);printf("是否继续借阅？是...1否...0\n");scanf("%d", &retry);system("pause"); system("cls");continue;}else if (STU.Students[stu].current_number == STU.Students[stu].max_number) {L.Books[bk].book_quantity--;printf("借阅一本%s\n", L.Books[bk].book_name);printf("借书数量达到上限\n");system("pause"); system("cls");retry = 0;}}}} while (retry == 1);printf("退出借书功能\n");
}
int main()
{system("color 71");int sl, log, check, restart;Library L;Initial_Library(L);StudentsData STU;Initial_Students(STU);do {restart = 0;log = Login(STU);do {start:system("cls");printf("功能选择\n查询当前借阅状态...1\n借阅图书...2\n退出登录...0\n");scanf("%d", &sl);switch (sl){case 0:restart = 1; system("pause"); system("cls"); break;case 1:Display_Student(STU, log); system("pause"); system("cls"); break;case 2:system("cls");if (STU.Students[log].current_number >= STU.Students[log].max_number) {printf("借书数量达到上限 不可继续借阅\n");system("pause"); system("cls");break;}else {Borrow_Book(L, STU, log);system("pause"); system("cls");break;}default:goto start;break;}} while (restart == 0);} while (restart == 1);}