drd/学籍管理系统6.cpp

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

// 定义学生结构体，包含学号、班级、姓名以及三门课程成绩
typedef struct Student {
    int id;
    int class_num;
    char name[20];
    double score1;
    double score2;
    double score3;
} Student;

// 交换两个学生结构体的函数
void swap(Student *a, Student *b) {
    Student temp = *a;
    *a = *b;
    *b = temp;
}

// 计算学生的总成绩
double totalScore(const Student *s) {
    return s->score1 + s->score2 + s->score3;
}

// 根据学号查找学生在数组中的索引位置，若没找到返回 -1
int findStudentIndex(Student students[], int num_students, int target_id) {
    for (int i = 0; i < num_students; i++) {
        if (students[i].id == target_id) {
            return i;
        }
    }
    return -1;
}

// 修改指定学号的学生信息，并重新调整数组顺序以保持有序
void modifyStudent(Student students[], int *num_students, Student new_student) {
    int index = findStudentIndex(students, *num_students, new_student.id);
    if (index!= -1) {
        students[index] = new_student;
        // 从修改位置开始，向前比较调整顺序（保证班级从小到大，同一班级内总成绩从大到小）
        for (int i = index; i > 0; i--) {
            if (students[i].class_num < students[i - 1].class_num) {
                swap(&students[i], &students[i - 1]);
            } else if (students[i].class_num == students[i - 1].class_num) {
                double cur_total = totalScore(&students[i]);
                double prev_total = totalScore(&students[i - 1]);
                if (cur_total > prev_total) {
                    swap(&students[i], &students[i - 1]);
                } else {
                    break;
                }
            } else {
                break;
            }
        }
        // 从修改位置开始，向后比较调整顺序
        for (int i = index; i < *num_students - 1; i++) {
            if (students[i].class_num > students[i + 1].class_num) {
                swap(&students[i], &students[i + 1]);
            } else if (students[i].class_num == students[i + 1].class_num) {
                double cur_total = totalScore(&students[i]);
                double next_total = totalScore(&students[i + 1]);
                if (cur_total < next_total) {
                    swap(&students[i], &students[i + 1]);
                } else {
                    break;
                }
            } else {
                break;
            }
        }
    }
}

// 按照要求格式打印学生数组信息，同一班级的学生除第一个外缩进显示，且标记修改的学生
void printStudents(Student students[], int num_students) {
    int current_class = students[0].class_num;
    for (int i = 0; i < num_students; i++) {
        if (students[i].class_num == current_class) {
            if (i == 0) {
                printf("%d %d %s %.1lf %.1lf %.1lf", students[i].class_num, students[i].id, students[i].name,
                       students[i].score1, students[i].score2, students[i].score3);
            } else {
                printf("   %d %s %.1lf %.1lf %.1lf", students[i].id, students[i].name, students[i].score1, students[i].score2, students[i].score3);
            }
            if (i == num_students - 1 && findStudentIndex(students, num_students, students[i].id)!= -1) {
                printf(" modified\n");
            } else {
                printf("\n");
            }
        } else {
            current_class = students[i].class_num;
            printf("%d %d %s %.1lf %.1lf %.1lf\n", students[i].class_num, students[i].id, students[i].name,
                   students[i].score1, students[i].score2, students[i].score3);
        }
    }
}

int main() {
    Student students[100];  // 假设最多存储100个学生信息，可根据实际情况调整大小
    int num_students = 3;   // 初始已有3个学生信息

    // 静态初始化已有三个学生信息（按题目给定示例）
    Student s1 = {10001, 11, "Zhang", 99.5, 88.5, 89.5};
    Student s2 = {10002, 12, "Yang", 77.9, 56.5, 87.5};
    Student s3 = {10003, 11, "Liang", 92.5, 99.0, 60.5};
    students[0] = s1;
    students[1] = s2;
    students[2] = s3;

    Student new_student;
    printf("please input:\n");
    scanf("%d %d %s %lf %lf %lf", &new_student.id, &new_student.class_num, &new_student.name, &new_student.score1, &new_student.score2, &new_student.score3);

    // 查找要修改的学生是否存在
    int exist = findStudentIndex(students, num_students, new_student.id);
    if (exist == -1) {
        // 如果学生不存在，直接输出原有学生信息并结束程序
        printStudents(students, num_students);
        return 0;
    }

    // 如果学生存在，修改学生信息并输出更新后的信息
    modifyStudent(students, &num_students, new_student);
    printStudents(students, num_students);

    return 0;
}