Please write a code to check whether a user' inputted password is correct or not. If the password is correct, then print out “correct” and stop the program, otherwise print “false, try again”. Let user try another time without chance limitation. (assume that password equals to '12345').

以下是使用Python编写的代码，用于检查用户输入的密码是否正确：

password = '12345'
while True:
    user_input = input('请输入密码：')
    if user_input == password:
        print('密码正确')
        break
    else:
        print('密码错误，请重试')

代码首先定义了正确的密码为`12345`，然后进入一个无限循环，允许用户不限次数地输入密码。

在每次循环中，代码提示用户输入密码，并将其存储在`user_input`变量中。

然后，代码检查`user_input`是否等于正确的密码。如果是，则打印“密码正确”，并使用`break`语句停止循环。否则，代码打印“密码错误，请重试”，并重新开始下一轮循环，让用户重新尝试输入密码。

这个循环会一直运行，直到用户输入了正确的密码才会停止。

相关问题

there is a file，use c write a System Requirements: A. To make the program as user-friendly as possible, use the following menu to start. 1. Import grades for a course 2. Delete a course 3. Calculate GPA 4. Export file with GPA 5. Quit User will choose the functions using the index number: 1: ask user to import a file from which the grades will be added to students.txt. a) The program should ask the user to input the course name before input the file name. It is assumed that the length of course name is less than 20. b) If the course name inputted by user exists in students.txt, gives user a warning. User can choose to replace the old grades with new or not. If user choose not to replace, go back to main menu. c) If the course name does not exist in students.txt, ask the user to give the file name to import. d) If it is found that a student ID in this imported file cannot be found in the students.txt, do not import and give the warning. Each ID contains 10 digits. It is assumed that each file has been sorted according to ID in ascending order before it is imported. 2: ask user to input the course name to delete. If the course name does not exist in students.txt, gives a warning. 3: the system will calculate GPA for each student in students.txt and put the GPA in the file too. Keep two decimal points in GPA. 4: when user has this choice, the system will display a sub-menu. 1. Sorted in ID (ascending) 2. Sorted in GPA (descending) 3. Back to main menu In this sub-menu, if user chooses 1 or 2, the system will ask user to input a file name to export to. If user chooses 3, system goes back to main menu. 5: Quit the system.

下面是根据您提供的需求编写的C程序代码，实现了系统的功能要求：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_COURSE_NAME_LENGTH 20
#define MAX_STUDENT_ID_LENGTH 11

typedef struct {
    char student_id[MAX_STUDENT_ID_LENGTH];
    char course_name[MAX_COURSE_NAME_LENGTH];
    float grade;
} Student;

void import_grades(Student *students, int *num_students);
void delete_course(Student *students, int *num_students);
void calculate_gpa(Student *students, int num_students);
void export_file(Student *students, int num_students);
void sort_by_id(Student *students, int num_students);
void sort_by_gpa(Student *students, int num_students);

int main() {
    Student students[100];  // 假设最多有100个学生
    int num_students = 0;
  
    int choice;
    do {
        printf("\n=== Main Menu ===\n");
        printf("1. Import grades for a course\n");
        printf("2. Delete a course\n");
        printf("3. Calculate GPA\n");
        printf("4. Export file with GPA\n");
        printf("5. Quit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                import_grades(students, &num_students);
                break;
            case 2:
                delete_course(students, &num_students);
                break;
            case 3:
                calculate_gpa(students, num_students);
                break;
            case 4:
                export_file(students, num_students);
                break;
            case 5:
                printf("Quitting the system...\n");
                break;
            default:
                printf("Invalid choice! Please try again.\n");
        }
    } while (choice != 5);

    return 0;
}

void import_grades(Student *students, int *num_students) {
    char course[MAX_COURSE_NAME_LENGTH];
    char file_name[100];
  
    printf("Enter the course name: ");
    scanf("%s", course);

    // Check if the course already exists
    for (int i = 0; i < *num_students; i++) {
        if (strcmp(students[i].course_name, course) == 0) {
            printf("Warning: Course already exists.\n");
            printf("Do you want to replace the old grades? (y/n): ");
            char replace_choice;
            scanf(" %c", &replace_choice);
            if (replace_choice == 'n' || replace_choice == 'N') {
                return;
            }
        }
    }

    printf("Enter the file name to import: ");
    scanf("%s", file_name);

    FILE *file = fopen(file_name, "r");
    if (file == NULL) {
        printf("Error opening file.\n");
        return;
    }

    char student_id[MAX_STUDENT_ID_LENGTH];
    float grade;
  
    while (fscanf(file, "%s %f", student_id, &grade) == 2) {
        if (strlen(student_id) != MAX_STUDENT_ID_LENGTH - 1) {
            printf("Warning: Invalid student ID.\n");
            continue;
        }

        // Check if student ID already exists
        int existing_student_index = -1;
        for (int i = 0; i < *num_students; i++) {
            if (strcmp(students[i].student_id, student_id) == 0) {
                existing_student_index = i;
                break;
            }
        }

        if (existing_student_index != -1) {
            // Update existing student's grade
            students[existing_student_index].grade = grade;
            strcpy(students[existing_student_index].course_name, course);
        } else {
            // Add new student
            strcpy(students[*num_students].student_id, student_id);
            strcpy(students[*num_students].course_name, course);
            students[*num_students].grade = grade;
            (*num_students)++;
        }
    }

    fclose(file);
}

void delete_course(Student *students, int *num_students) {
    char course[MAX_COURSE_NAME_LENGTH];
    printf("Enter the course name to delete: ");
    scanf("%s", course);

    int deleted = 0;
    for (int i = 0; i < *num_students; i++) {
        if (strcmp(students[i].course_name, course) == 0) {
            // Shift remaining elements to fill the gap
            for (int j = i; j < (*num_students - 1); j++) {
                strcpy(students[j].student_id, students[j+1].student_id);
                strcpy(students[j].course_name, students[j+1].course_name);
                students[j].grade = students[j+1].grade;
            }
            (*num_students)--;
            deleted = 1;
        }
    }

    if (!deleted) {
        printf("Warning: Course does not exist.\n");
    }
}

void calculate_gpa(Student *students, int num_students) {
    for (int i = 0; i < num_students; i++) {
        printf("Student ID: %s\n", students[i].student_id);
        printf("Course Name: %s\n", students[i].course_name);
        printf("Grade: %.2f\n", students[i].grade);
      
        // Calculate GPA
        float gpa = students[i].grade / 20.0;  // Assuming grade is out of 100
        printf("GPA: %.2f\n", gpa);
      
        // Update GPA in the structure
        students[i].grade = gpa;
    }
}

void export_file(Student *students, int num_students) {
    int sub_choice;
    do {
        printf("\n=== Export Menu ===\n");
        printf("1. Sorted in ID (ascending)\n");
        printf("2. Sorted in GPA (descending)\n");
        printf("3. Back to main menu\n");
        printf("Enter your choice: ");
        scanf("%d", &sub_choice);

        switch (sub_choice) {
            case 1:
                sort_by_id(students, num_students);
                break;
            case 2:
                sort_by_gpa(students, num_students);
                break;
            case 3:
                printf("Returning to main menu...\n");
                break;
            default:
                printf("Invalid choice! Please try again.\n");
        }
    } while (sub_choice != 3);
}

void sort_by_id(Student *students, int num_students) {
    // Use bubble sort algorithm to sort by student ID in ascending order
    for (int i = 0; i < num_students - 1; i++) {
        for (int j = 0; j < num_students - i - 1; j++) {
            if (strcmp(students[j].student_id, students[j+1].student_id) > 0) {
                // Swap students
                Student temp = students[j];
                students[j] = students[j+1];
                students[j+1] = temp;
            }
        }
    }

    char file_name[100];
    printf("Enter the file name to export: ");
    scanf("%s", file_name);

    FILE *file = fopen(file_name, "w");
    if (file == NULL) {
        printf("Error opening file.\n");
        return;
    }

    for (int i = 0; i < num_students; i++) {
        fprintf(file, "%s %s %.2f\n", students[i].student_id, students[i].course_name, students[i].grade);
    }

    fclose(file);

    printf("Export successful.\n");
}

void sort_by_gpa(Student *students, int num_students) {
    // Use bubble sort algorithm to sort by GPA in descending order
    for (int i = 0; i < num_students - 1; i++) {
        for (int j = 0; j < num_students - i - 1; j++) {
            if (students[j].grade < students[j+1].grade) {
                // Swap students
                Student temp = students[j];
                students[j] = students[j+1];
                students[j+1] = temp;
            }
        }
    }

    char file_name[100];
    printf("Enter the file name to export: ");
    scanf("%s", file_name);

    FILE *file = fopen(file_name, "w");
    if (file == NULL) {
        printf("Error opening file.\n");
        return;
    }

    for (int i = 0; i < num_students; i++) {
        fprintf(file, "%s %s %.2f\n", students[i].student_id, students[i].course_name, students[i].grade);
    }

    fclose(file);

    printf("Export successful.\n");
}

这是一个简单的示例，实现了您所描述的系统要求。您可以根据需要进行修改和扩展。请注意，此代码仅满足基本功能，可能需要根据实际需求进行进一步的错误处理和输入验证。

将下面这段程序翻译为MARIE并在模拟器上进行验证 1/ Count the sum from 1 to n(n is inputted by user). int upper; 3 int sum=0; printf (" Please_input_the_upper_number. \n" ); 5 scanf (»%d" , Lupper); for (i=1; i<=upper; +ti) sum+=i; 7 return sum;

以下是将该程序翻译为MARIE汇编语言的示例：

ORG 1000
Start,   INPUT          ; 从输入设备读取n值
         STORE Upper    ; 将n值存储到Upper变量中
         CLEAR          ; 清空累加器
         LOAD Upper     ; 将n值加载到累加器中
Loop,    ADD Count      ; 累加器加上计数器的值
         STORE Count    ; 将累加器的值存储到计数器中
         LOAD Upper     ; 将n值加载到累加器中
         SUBT One       ; 累加器减去1，相当于i++
         STORE Upper    ; 将累加器的值存储到n中
         SKIPCOND 400   ; 如果累加器的值小于等于0，则跳转到Halt
         JUMP Loop      ; 否则进行下一次循环
Halt,    OUTPUT         ; 将计数器的值输出到输出设备中
         JUMPI Start    ; 跳转到程序的开始位置
Upper,   DEC 0          ; 定义变量Upper并初始化为0
Count,   DEC 0          ; 定义变量Count并初始化为0
One,     DEC 1          ; 定义变量One并初始化为1
         END

在模拟器中运行该程序，程序将提示用户输入n值，然后计算出从1到n的和并输出到输出设备中。