学生成绩分析系统C++

一个学生成绩分析系统可以有以下功能：

1. 输入学生信息和成绩数据
2. 统计每个学生的总分和平均分
3. 统计每个科目的平均分和总分
4. 输出每个学生的成绩单，包括每个科目的成绩、总分和平均分
5. 输出所有学生的平均分和总分
6. 根据学生的总分或平均分进行排序并输出排名

下面是一个简单的C++程序示例：

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

// 学生信息结构体
struct Student {
    string name; // 姓名
    int id; // 学号
    vector<int> scores; // 分数
    int total_score; // 总分
    double avg_score; // 平均分
};

// 计算学生总分和平均分
void calc_student_score(Student& s) {
    s.total_score = 0;
    for (int score : s.scores) {
        s.total_score += score;
    }
    s.avg_score = static_cast<double>(s.total_score) / s.scores.size();
}

// 计算每个科目的平均分和总分
void calc_subject_score(const vector<Student>& students, vector<int>& subject_total_scores, vector<double>& subject_avg_scores) {
    subject_total_scores.clear();
    subject_avg_scores.clear();
    int num_subjects = students[0].scores.size();
    subject_total_scores.resize(num_subjects, 0);
    subject_avg_scores.resize(num_subjects, 0.0);
    for (const Student& s : students) {
        for (int i = 0; i < num_subjects; i++) {
            subject_total_scores[i] += s.scores[i];
        }
    }
    for (int i = 0; i < num_subjects; i++) {
        subject_avg_scores[i] = static_cast<double>(subject_total_scores[i]) / students.size();
    }
}

// 输出学生信息和成绩
void print_student(const Student& s) {
    cout << "姓名: " << s.name << endl;
    cout << "学号: " << s.id << endl;
    cout << "成绩: ";
    for (int score : s.scores) {
        cout << score << " ";
    }
    cout << endl;
    cout << "总分: " << s.total_score << endl;
    cout << "平均分: " << s.avg_score << endl;
}

// 输出所有学生的平均分和总分
void print_summary(const vector<Student>& students) {
    int total_score = 0;
    double avg_score = 0.0;
    for (const Student& s : students) {
        total_score += s.total_score;
        avg_score += s.avg_score;
    }
    avg_score /= students.size();
    cout << "所有学生总分: " << total_score << endl;
    cout << "所有学生平均分: " << avg_score << endl;
}

// 按总分排序比较函数
bool compare_total_score(const Student& s1, const Student& s2) {
    return s1.total_score > s2.total_score;
}

// 按平均分排序比较函数
bool compare_avg_score(const Student& s1, const Student& s2) {
    return s1.avg_score > s2.avg_score;
}

int main() {
    vector<Student> students;
    vector<int> subject_total_scores;
    vector<double> subject_avg_scores;

    // 输入学生信息和成绩数据
    int num_students, num_subjects;
    cout << "请输入学生人数: ";
    cin >> num_students;
    cout << "请输入科目数: ";
    cin >> num_subjects;
    students.resize(num_students);
    for (int i = 0; i < num_students; i++) {
        cout << "请输入第" << i + 1 << "个学生的姓名和学号: ";
        cin >> students[i].name >> students[i].id;
        students[i].scores.resize(num_subjects);
        cout << "请输入第" << i + 1 << "个学生的成绩: ";
        for (int j = 0; j < num_subjects; j++) {
            cin >> students[i].scores[j];
        }
        calc_student_score(students[i]);
    }

    // 统计每个科目的平均分和总分
    calc_subject_score(students, subject_total_scores, subject_avg_scores);

    // 输出每个科目的平均分和总分
    cout << "每个科目的总分和平均分: " << endl;
    for (int i = 0; i < num_subjects; i++) {
        cout << "科目" << i + 1 << "总分: " << subject_total_scores[i] << endl;
        cout << "科目" << i + 1 << "平均分: " << subject_avg_scores[i] << endl;
    }

    // 输出每个学生的成绩单
    cout << "每个学生的成绩单: " << endl;
    for (const Student& s : students) {
        print_student(s);
    }

    // 输出所有学生的平均分和总分
    print_summary(students);

    // 按总分排序并输出排名
    sort(students.begin(), students.end(), compare_total_score);
    cout << "按总分排名: " << endl;
    for (int i = 0; i < num_students; i++) {
        cout << "第" << i + 1 << "名: " << students[i].name << " 总分: " << students[i].total_score << endl;
    }

    // 按平均分排序并输出排名
    sort(students.begin(), students.end(), compare_avg_score);
    cout << "按平均分排名: " << endl;
    for (int i = 0; i < num_students; i++) {
        cout << "第" << i + 1 << "名: " << students[i].name << " 平均分: " << students[i].avg_score << endl;
    }

    return 0;
}