用c语言编写学生成绩管理实现功能：输入、输出、插入、删除、查找、追加、读入、显示、保存、拷贝、排序、索引、分类合计、退出。

以下是用C语言编写学生成绩管理实现各种功能的示例代码：

1. 输入学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void inputScore(struct Student *student) {
    printf("请输入学生的成绩：\n");
    printf("大学英语成绩：");
    scanf("%f", &(student->english));
    printf("毛概成绩：");
    scanf("%f", &(student->politics));
    printf("数据结构成绩：");
    scanf("%f", &(student->dataStructure));
    printf("数据库成绩：");
    scanf("%f", &(student->database));
}

2. 输出学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void outputScore(struct Student student) {
    printf("学生的成绩如下：\n");
    printf("大学英语成绩：%f\n", student.english);
    printf("毛概成绩：%f\n", student.politics);
    printf("数据结构成绩：%f\n", student.dataStructure);
    printf("数据库成绩：%f\n", student.database);
}

3. 插入学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void insertScore(struct Student *student, float english, float politics, float dataStructure, float database) {
    student->english = english;
    student->politics = politics;
    student->dataStructure = dataStructure;
    student->database = database;
}

4. 删除学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void deleteScore(struct Student *student) {
    student->english = 0;
    student->politics = 0;
    student->dataStructure = 0;    student->database = 0;
}

5. 查找学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void searchScore(struct Student student) {
    printf("学生的成绩如下：\n");
    printf("大学英语成绩：%f\n", student.english);
    printf("毛概成绩：%f\n", student.politics);
    printf("数据结构成绩：%f\n", student.dataStructure);
    printf("数据库成绩：%f\n", student.database);
}

6. 追加学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void appendScore(struct Student *student, float english, float politics, float dataStructure, float database) {
    student->english += english;
    student->politics += politics;
    student->dataStructure += dataStructure;
    student->database += database;
}

7. 读入学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void readScore(struct Student *student) {
    printf("请输入学生的成绩：\n");
    printf("大学英语成绩：");
    scanf("%f", &(student->english));
    printf("毛概成绩：");
    scanf("%f", &(student->politics));
    printf("数据结构成绩：");
    scanf("%f", &(student->dataStructure));
    printf("数据库成绩：");
    scanf("%f", &(student->database));
}

8. 显示学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void displayScore(struct Student student) {
    printf("学生的成绩如下：\n");
    printf("大学英语成绩：%f\n", student.english);
    printf("毛概成绩：%f\n", student.politics);
    printf("数据结构成绩：%f\n", student.dataStructure);
    printf("数据库成绩：%f\n", student.database);
}

9. 保存学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void saveScore(struct Student student) {
    FILE *file = fopen("score.txt", "w");
    if (file == NULL) {
        printf("保存失败！\n");
        return;
    }
    fprintf(file, "大学英语成绩：%f\n", student.english);
    fprintf(file, "毛概成绩：%f\n", student.politics);
    fprintf(file, "数据结构成绩：%f\n", student.dataStructure);
    fprintf(file, "数据库成绩：%f\n", student.database);
    fclose(file);
    printf("保存成功！\n");
}

10. 拷贝学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void copyScore(struct Student *dest, struct Student src) {
    dest->english = src.english;
    dest->politics = src.politics;
    dest->dataStructure = src.dataStructure;
    dest->database = src.database;
}

11. 排序学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void sortScore(struct Student *students, int count) {
    // 使用冒泡排序按照大学英语成绩从小到大排序
    for (int i = 0; i < count - 1; i++) {
        for (int j = 0; j < count - i - 1; j++) {
            if (students[j].english > students[j + 1].english) {
                struct Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
}

12. 索引学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void indexScore(struct Student *students, int count) {
    printf("学生成绩索引如下：\n");
    for (int i = 0; i < count; i++) {
        printf("学生%d的大学英语成绩：%f\n", i + 1, students[i].english);
    }
}

13. 分类合计学生成绩：

#include <stdio.h>

struct Student {
    float english;
    float politics;
    float dataStructure;
    float database;
};

void sumScore(struct Student *students, int count) {
    float englishSum = 0;
    float politicsSum = 0;
    float dataStructureSum = 0;
    float databaseSum = 0;
    for (int i = 0; i < count; i++) {
        englishSum += students[i].english;
        politicsSum += students[i].politics;
        dataStructureSum += students[i].dataStructure;
        databaseSum += students[i].database;
    }
    printf("大学英语成绩总和：%f\n", englishSum);
    printf("毛概成绩总和：%f\n", politicsSum);
    printf("数据结构成绩总和：%f\n", dataStructureSum);
    printf("数据库成绩总和：%f\n", databaseSum);
}

14. 退出程序：

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

void exitProgram() {
    printf("程序已退出！\n");
    exit(0);
}