#学生成绩管理系统（用c语言实现）#

Question

学生成绩管理系统（用c语言实现）
1、问题描述设计一个简单的学生成绩管理系统，可录入、保存一个班级学生多门课程的成绩，并对成绩进行分析。2、基本要求（1）输入各学生多门课程的成绩，并存储；（2）按各门课程成绩排序，并生成相应的文件输出；（3）计算每人的平均成绩，按平均成绩排序，并生成文件；（4）求出各门课程的平均成绩、最高分、最低分、不及格人数、60-69 分人数，70-79 分人数、80-89 分人数、90 分以上人数；（5）根据姓名或学号查询某人的各门课成绩，重名情况也能处理
解题思路：1. 数据结构选择：可以使用二维数组存储学生成绩。2. 信息输入与存储：录入学生多门课程成绩，存储在二维数组中。3. 排序与文件输出：按课程成绩排序，生成文件；按平均成绩排序，生成文件。4. 统计分析：计算并输出各课程的平均成绩、最高分、最低分及各分数段人数。5. 查询功能：按姓名或学号查询学生成绩，需处理重名情况。

Answer 1

这个代码应该能实现你的要求，就是不知道版本环境是否适配。

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

#define MAX_STUDENTS 100
#define MAX_SUBJECTS 10
#define NAME_LEN 50

// 学生结构体
typedef struct {
    char name[NAME_LEN];
    int student_id;
    float scores[MAX_SUBJECTS];
    float average;
} Student;

// 科目结构体
typedef struct {
    char name[NAME_LEN];
    float scores[MAX_STUDENTS];
    float average;
    float max_score;
    float min_score;
    int count_60_69;
    int count_70_79;
    int count_80_89;
    int count_90_above;
    int fail_count;
} Subject;

// 全局变量存储学生和课程信息
Student students[MAX_STUDENTS];
Subject subjects[MAX_SUBJECTS];
int student_count = 0;
int subject_count = 0;

// 录入课程信息
void input_subjects() {
    printf("请输入课程数量: ");
    scanf("%d", &subject_count);
    for (int i = 0; i < subject_count; i++) {
        printf("请输入课程名称: ");
        scanf("%s", subjects[i].name);
        subjects[i].max_score = 0;
        subjects[i].min_score = 100;
        subjects[i].count_60_69 = 0;
        subjects[i].count_70_79 = 0;
        subjects[i].count_80_89 = 0;
        subjects[i].count_90_above = 0;
        subjects[i].fail_count = 0;
        subjects[i].average = 0.0;
    }
}

// 录入学生成绩信息
void input_student_scores() {
    printf("请输入学生姓名: ");
    scanf("%s", students[student_count].name);
    printf("请输入学生学号: ");
    scanf("%d", &students[student_count].student_id);
    
    float total = 0.0;
    for (int j = 0; j < subject_count; j++) {
        printf("请输入%s成绩: ", subjects[j].name);
        scanf("%f", &students[student_count].scores[j]);
    
        // 更新学科成绩信息
        subjects[j].scores[student_count] = students[student_count].scores[j];
        
        // 更新课程平均分
        subjects[j].average += students[student_count].scores[j] / student_count;

        // 更新课程最高分、最低分
        if (students[student_count].scores[j] > subjects[j].max_score) {
            subjects[j].max_score = students[student_count].scores[j];
        }

        if (students[student_count].scores[j] < subjects[j].min_score) {
            subjects[j].min_score = students[student_count].scores[j];
        }

        // 统计各分数段人数
        if (students[student_count].scores[j] >= 90) {
            subjects[j].count_90_above++;
        } else if (students[student_count].scores[j] >= 80) {
            subjects[j].count_80_89++;
        } else if (students[student_count].scores[j] >= 70) {
            subjects[j].count_70_79++;
        } else if (students[student_count].scores[j] >= 60) {
            subjects[j].count_60_69++;
        } else {
            subjects[j].fail_count++;
        }

        // 更新学生成绩总分
        total += students[student_count].scores[j];
    }

    // 计算并存储学生平均分
    students[student_count].average = total / subject_count;
    student_count++;
}

// 按课程成绩排序
void sort_by_subject(int subject_index) {
    for (int i = 0; i < student_count - 1; ++i) {
        for (int j = 0; j < student_count - 1 - i; ++j) {
            if (students[j].scores[subject_index] < students[j + 1].scores[subject_index]) {
                Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
}

// 按平均成绩排序
void sort_by_average() {
    for (int i = 0; i < student_count - 1; ++i) {
        for (int j = 0; j < student_count - 1 - i; ++j) {
            if (students[j].average < students[j + 1].average) {
                Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
}

// 统计各科目的统计数据
void calculate_statistics() {
    for (int i = 0; i < subject_count; ++i) {
        subjects[i].average = 0.0;
        for (int j = 0; j < student_count; ++j) {
            subjects[i].average += subjects[i].scores[j];
        }
        subjects[i].average /= student_count;
    }
}

// 导出成绩到文件
void export_scores(const char *filename, int by_subject) {
    FILE *fp = fopen(filename, "w");
    if (fp == NULL) {
        printf("无法创建文件\n");
        return;
    }

    if (by_subject) {
        for (int i = 0; i < subject_count; ++i) {
            fprintf(fp, "课程：%s\n", subjects[i].name);
            for (int j = 0; j < student_count; ++j) {
                fprintf(fp, "学生：%s，成绩：%.2f\n", students[j].name, students[j].scores[i]);
            }
            fprintf(fp, "\n");
        }
    } else {
        for (int i = 0; i < student_count; ++i) {
            fprintf(fp, "学生：%s，平均成绩：%.2f\n", students[i].name, students[i].average);
        }
    }

    fclose(fp);
}

// 查询某个学生的成绩
void query_student() {
    char query[NAME_LEN];
    printf("请输入要查询的学生姓名或学号：");
    scanf("%s", query);

    for (int i = 0; i < student_count; ++i) {
        if (strcmp(students[i].name, query) == 0 || atoi(query) == students[i].student_id) {
            printf("学生：%s，学号：%d\n", students[i].name, students[i].student_id);
            for (int j = 0; j < subject_count; ++j) {
                printf("%s：%.2f\n", subjects[j].name, students[i].scores[j]);
            }
            return;
        }
    }

    printf("未找到该学生\n");
}

int main() {
    int choice;

    // 录入课程信息
    input_subjects();

    // 主循环
    while (1) {
        printf("\n1. 录入学生成绩\n");
        printf("2. 按成绩排序并导出\n");
        printf("3. 按平均成绩排序并导出\n");
        printf("4. 统计各科目数据\n");
        printf("5. 查询学生成绩\n");
        printf("6. 退出\n");

        printf("请选择操作： ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                input_student_scores();
                break;
            case 2:
                for (int i = 0; i < subject_count; ++i) {
                    sort_by_subject(i);
                }
                export_scores("subject_scores.txt", 1);
                break;
            case 3:
                sort_by_average();
                export_scores("average_scores.txt", 0);
                break;
            case 4:
                calculate_statistics();
                for (int i = 0; i < subject_count; ++i) {
                    printf("\n课程：%s\n", subjects[i].name);
                    printf("平均成绩：%.2f\n", subjects[i].average);
                    printf("最高成绩：%.2f\n", subjects[i].max_score);
                    printf("最低成绩：%.2f\n", subjects[i].min_score);
                    printf("不及格人数：%d\n", subjects[i].fail_count);
                    printf("60-69分人数：%d\n", subjects[i].count_60_69);
                    printf("70-79分人数：%d\n", subjects[i].count_70_79);
                    printf("80-89分人数：%d\n", subjects[i].count_80_89);
                    printf("90分以上人数：%d\n", subjects[i].count_90_above);
                }
                break;
            case 5:
                query_student();
                break;
            case 6:
                exit(0);
                break;
            default:
                printf("无效输入，请重试\n");
                break;
        }
    }

    return 0;
}