用C语言和Java编写同一个功能的应用程序，实现下列功能：输入20名同学的学号、姓名、三门课程成绩；计算每位同学的总分与平均分；输出成绩表、显示总分最高分与最低分学生的成绩信息。

在C语言和Java中，你可以使用类似的数据结构和算法来实现这个功能。这里是一个简化的例子：

C语言实现：

#include <stdio.h>

typedef struct {
    int id;
    char name[50];
    float score[3];
} Student;

void input_students(Student students[], int num) {
    for (int i = 0; i < num; i++) {
        printf("请输入学生 %d 的信息：\n", i + 1);
        scanf("%d", &students[i].id);
        fgets(students[i].name, sizeof(students[i].name), stdin);
        for (int j = 0; j < 3; j++) {
            scanf("%f", &students[i].score[j]);
        }
    }
}

void calculate_scores(Student students[], int num) {
    float max_score = students[0].score[0], min_score = students[0].score[0];
    for (int i = 1; i < num; i++) {
        float total = 0;
        for (int j = 0; j < 3; j++) {
            total += students[i].score[j];
        }
        students[i].total = total;
        students[i].avg = total / 3;
        if (total > max_score) {
            max_score = total;
        }
        if (total < min_score) {
            min_score = total;
        }
    }
}

void print_students(Student students[], int num) {
    for (int i = 0; i < num; i++) {
        printf("学号：%d, 姓名：%s, 总分：%f, 平均分：%f\n", 
               students[i].id, students[i].name, students[i].total, students[i].avg);
    }
    printf("最高分：%f - 学生：%s\n", max_score, find_student_with_max_score(students, num));
    printf("最低分：%f - 学生：%s\n", min_score, find_student_with_min_score(students, num));
}

// 辅助函数，查找总分最高的学生
Student* find_student_with_max_score(Student students[], int num) {
    Student *max_student = &students[0];
    for (int i = 1; i < num; i++) {
        if (students[i].total > max_student->total) {
            max_student = &students[i];
        }
    }
    return max_student;
}

// 辅助函数，查找总分最低的学生
Student* find_student_with_min_score(Student students[], int num) {
    Student *min_student = &students[0];
    for (int i = 1; i < num; i++) {
        if (students[i].total < min_student->total) {
            min_student = &students[i];
        }
    }
    return min_student;
}

int main() {
    int num_students = 20;
    Student students[num_students];
    input_students(students, num_students);
    calculate_scores(students, num_students);
    print_students(students, num_students);
    return 0;
}

Java实现：

import java.util.Scanner;

class Student {
    int id;
    String name;
    double[] scores;

    void input() {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入学生 " + id + " 的信息：");
        name = sc.nextLine();
        for (int i = 0; i < 3; i++) {
            scores[i] = sc.nextDouble();
        }
    }

    double getTotal() {
        double total = 0;
        for (double score : scores) {
            total += score;
        }
        return total;
    }

    double getAverage() {
        return getTotal() / 3;
    }

    // 省略辅助方法，如findMaxScore和findMinScore
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int numStudents = 20;
        Student[] students = new Student[numStudents];

        for (int i = 0; i < numStudents; i++) {
            Student s = new Student();
            s.id = i + 1;
            s.input();
            students[i] = s;
        }

        for (Student s : students) {
            System.out.printf("学号：%d, 姓名：%s, 总分：%f, 平均分：%f%n",
                    s.id, s.name, s.getTotal(), s.getAverage());
        }
        // 计算并输出最高分和最低分
        double maxScore = students[0].getTotal();
        double minScore = students[0].getTotal();

        for (Student s : students) {
            if (s.getTotal() > maxScore) {
                maxScore = s.getTotal();
            } else if (s.getTotal() < minScore) {
                minScore = s.getTotal();
            }
        }

        System.out.println("最高分：" + maxScore + " - 学生：" + findMaxScore(students)[0] + ", " + findMaxScore(students)[1]);
        System.out.println("最低分：" + minScore + " - 学生：" + findMinScore(students)[0] + ", " + findMinScore(students)[1]);

        sc.close();
    }
    
    // 辅助方法，查找总分最高的学生
    private static double[] findMaxScore(Student[] students) {
        // 实现...
    }

    // 辅助方法，查找总分最低的学生
    private static double[] findMinScore(Student[] students) {
        // 实现...
    }
}

以上两个示例展示了如何分别用C语言和Java实现同样的功能。在Java版本中，我还省略了`findMaxScore`和`findMinScore`的具体实现，因为它们类似于C语言中的辅助函数。