[C++知识库]C语言：学生成绩管理系统V1.0

要求：
（1）录入每个学生的学号和考试成绩；
（2）计算课程的总分和平均分；
（3）按成绩由高到低排出名次表；
（4）按学号由小到大排出成绩表；
（5）按学号查询学生排名及其考试成绩；
（6）按优秀（90~100）、良好（80~89）、中等（70~79）、及格（60~69）、不及格（0~59）5个类别，统计每个类别的人数以及所占的百分比；
（7）输出每个学生的学号、考试成绩。

#include<stdio.h>
int main()
{
    int b;//接收每次选择回车字符
    long choice; //输入的选择的输入学号
    int countx[6] = { 0 };//记录个分段的人数，方便计算占比
    int n, choice1, ret = 1;//n：学生人数。choice1：选择的功能。ret：判断输入学号是否正确。
    int mid = 0, ex = 0;
    long ID, ID_student[30] = { 0 };
    float scoer, scoer_student[30] = { 0 };
    float sum = 0, average = 0;
    printf("Input student number(n<30):\n");
    scanf("%d", &n);
    do
    {
        printf("Management for Students' scores\n");
        printf("1.Input record\n");
        printf("2.Caculate total and average score of course\n");
        printf("3.Sort in descending order by score\n");
        printf("4.Sort in ascending order by number\n");
        printf("5.Search by number\n");
        printf("6.Statistic analysis\n");
        printf("7.List record\n");
        printf("0.Exit\n");
        printf("Please Input your choice:\n");
        scanf("%d", &choice1);
        b = getchar();
        switch (choice1)
        {
        case 1:
            printf("Input student's ID, name and score:\n");
            for (int i = 0; i < n; i++)
            {
                char a;  //接收回车字符
                scanf("%ld%f", &ID, &scoer);
                a = getchar();
                ID_student[i] = ID;
                scoer_student[i] = scoer;
            }
            break;
        case 2:

            for (int j = 0; j < n; j++)
            {
                sum += scoer_student[j];
            }
            average = sum / n;
            printf("sum=%.0f,aver=%.2f\n", sum, average);
            break;
        case 3:

            for (int k = 0; k < n; k++)
            {
                float mid = scoer_student[k];
                long   ex = ID_student[k];
                for (int j = k + 1; j < n; j++)
                {
                    if (mid <= scoer_student[j])
                    {

                        scoer_student[k] = scoer_student[j];
                        scoer_student[j] = mid;
                        mid = scoer_student[k];
                        ID_student[k] = ID_student[j];
                        ID_student[j] = ex;
                        ex = ID_student[k];
                    }
                }
            }
            printf("Sort in descending order by score:\n");
            for (int j = 0; j < n; j++)
            {
                printf("%ld\t%.0f\n", ID_student[j], scoer_student[j]);
            }
            break;
        case 4:
            for (int l = 0; l < n; l++)
            {
                long mid2 = ID_student[l];
                float scoerchange = scoer_student[l];
                for (int m = l + 1; m < n; m++)
                {
                    if (mid2 >= ID_student[m])
                    {
                        ID_student[l] = ID_student[m];
                        ID_student[m] = mid2;
                        mid2 = ID_student[l];
                        scoer_student[l] = scoer_student[m];
                        scoer_student[m] = scoerchange;
                        scoerchange = scoer_student[l];
                    }
                }
            }
            printf("Sort in ascending order by number:\n");
            for (int i = 0; i < n; i++)
            {
                printf("%ld\t%.0f\n", ID_student[i], scoer_student[i]);
            }
            break;
        case 5:


            printf("Input the number you want to search:\n");
            scanf("%ld", &choice);
            for (int i = 0; i < n; i++)
            {
                if (choice == ID_student[i])
                {
                    printf("%ld\t%.0f\n", ID_student[i], scoer_student[i]);
                    ret++;
                }
            }
            if (ret == 1)
                printf("Not found!\n");
            break;
        case 6:

            for (int i = 0; i < n; i++)
            {
                if (scoer_student[i] < 60 && scoer_student[i] >= 0)
                {
                    countx[0]++;
                }
                if (scoer_student[i] >= 60 && scoer_student[i] < 70)
                {
                    countx[1]++;
                }
                if (scoer_student[i] >= 70 && scoer_student[i] < 80)
                {
                    countx[2]++;
                }
                if (scoer_student[i] >= 80 && scoer_student[i] < 90)
                {
                    countx[3]++;
                }
                if (scoer_student[i] >= 90 && scoer_student[i] < 100)
                {
                    countx[4]++;
                }
                if (scoer_student[i] == 100)
                {
                    countx[5]++;
                }
            }
            printf("<60\t%d\t%.2f%%\n", countx[0], (float)countx[0] * 100 / n);
            printf("%d-%d\t%d\t%.2f%%\n", 60, 69, countx[1], (float)countx[1] * 100 / n);
            printf("%d-%d\t%d\t%.2f%%\n", 70, 79, countx[2], (float)countx[2] * 100 / n);
            printf("%d-%d\t%d\t%.2f%%\n", 80, 89, countx[3], (float)countx[3] * 100 / n);
            printf("%d-%d\t%d\t%.2f%%\n", 90, 99, countx[4], (float)countx[4] * 100 / n);
            printf("%d\t%d\t%.2f%%\n", 100, countx[5], (float)countx[5] * 100 / n);
            break;
        case 7:
            for (int i = 0; i < n; i++)
            {
                printf("%ld\t%.0f\n", ID_student[i], scoer_student[i]);
            }
            break;
        case 0:
            printf("End of program!\n");
            break;
        default:
            printf("Input error!\n");
            break;
        }
    } while (choice1 != 0);
    return 0;
}

测试：

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此题有明显的各部分功能，所以还可采用函数来实现各部分的功能，这里就不写了........

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注：编者水平有限，若有更好的方法欢迎在评论区提出讨论。