(1) 每个学生的学号和四门功课的成绩从键盘读入。
(2) 计算每个学生的总分、平均分。
(3) 按平均成绩进行排序，输出排序后的成绩单（包括学号、四门功课的成绩、总分、平均分），给出名次。如果分数相同，则名次并列，其他学生名次不变。
实验步骤与要求：
 (1) 每个功能为一个独立的函数。
 (2) 调试程序时，可先输入少量学生的成绩作为实验数据。如可输入3名学 生4门课成绩

#if 1

#include <stdio.h>

typedef struct score
{
    float subject1;
    float subject2;
    float subject3;
    float subject4;
    float totalScore;
    float averageScore;
}SCO;

typedef struct student
{
    unsigned long id;
    unsigned int ranknum;
    SCO score;
}STU;

STU stus[100];

void getMes(int &stuNum)
{
    int stuCount = 0;
    char sel;
    printf("进行学生信息录入：\n");
    do 
    {
        printf("请输入第%d个学生学号：",stuCount+1);
        scanf("%u",&(stus[stuCount].id));
        while (!getchar());
        printf("请输入该生成绩1：");
        scanf("%f", &(stus[stuCount].score.subject1));
        while (!getchar());
        printf("请输入该生成绩2：");
        scanf("%f", &(stus[stuCount].score.subject2));
        while (!getchar());
        printf("请输入该生成绩3：");
        scanf("%f", &(stus[stuCount].score.subject3));
        while (!getchar());
        printf("请输入该生成绩4：");
        scanf("%f", &(stus[stuCount].score.subject4));
        while (!getchar());
        printf("是否继续学生信息录入(y/n)：");
        scanf("%c", &sel);
        while (!getchar());
        if ('n' == sel)
        {
            printf("共计录入%d人,结束录入\n",stuCount+1);
            stuNum = stuCount + 1;
            break;
        }
        stuCount++;

    } while (1);
}

void get_aver_total(int stuNum)
{
    for (int i = 0; i < stuNum; ++i)
    {
        stus[i].score.totalScore = stus[i].score.subject1 + stus[i].score.subject2
            + stus[i].score.subject3 + stus[i].score.subject4;
        stus[i].score.averageScore = stus[i].score.totalScore / 4;
    }
}

void rankByAverage(int stuNum)
{
    STU stuTemp;
    for (int i = 0; i < stuNum - 1;++i)
    {
        for (int j = 0; j < stuNum - i;++j)
        {
            if (stus[j].score.averageScore < stus[j+1].score.averageScore)
            {
                stuTemp = stus[j];
                stus[j] = stus[j+1];
                stus[j+1] = stuTemp;
            }
        }
    }
    for (int i = 0; i < stuNum; ++i)
    {
        stus[i].ranknum = i + 1;
        if (stus[i].score.averageScore == stus[i + 1].score.averageScore)
        {
            stus[i + 1].ranknum = stus[i].ranknum;
            ++i;
        }
    }
}

void printMes(int stuNum)
{
    printf("id\tsub1\tsub2\tsub3\tsub4\ttotal\tave\tNo\n");
    for (int i = 0; i < stuNum; ++i)
    {
        printf("%u\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f\t%.2f\t%u\n",
            stus[i].id, stus[i].score.subject1, stus[i].score.subject2, stus[i].score.subject3
            , stus[i].score.subject4, stus[i].score.totalScore, stus[i].score.averageScore
            , stus[i].ranknum);
    }
}

int main()
{
    int stuNum;
    getMes(stuNum);             //录入学生信息
    get_aver_total(stuNum);     //求平均分和总分
    rankByAverage(stuNum);      //排序，计算名次
    printMes(stuNum);           //输出信息
    getchar();
}

#endif