C语言——学生管理系统（代码冗杂版）

主页面效果图如下：

代码如下：

#include<stdio.h>       //注意整个操作系统代码是基于WIndows系统，若用其他系统，运行代码时观感引起的不适见谅。
#include<stdlib.h>      //在Linux系统下可以将system（“cls”）改成system（“clear”），同样可以完成整段代码
#include<string.h>          

void Print_Menu();      //输出表单栏
void InputStu_Infor();      //录入学生信息
void Cal_Course_V();      //每门课的平均分
void Cal_Stu_V();         //每个学生的平均分
void Return_Menu();           //返回菜单栏函数       
void High_Short();              //从高到低排序并且输出
void Short_High();                //从低到高排序并且输出
void Stu_ID_Order();                //以学号排序
void Name_Dic();                    //以字典顺序排序并且输出
void FindStu_ID();                  //按照学号查找信息
void FindName();                    //按照名字查找信息
void Print_Level();                 //按照成绩划分优秀...
void Print_All();                   //打印所有已知信息
void Write_File();                    //写文件
void Read_File();                    //读文件

#define Average 0
#define MAX_Student_Num 30

int Num_class,Num_course;

typedef struct InFormation
{
    char name[25];      //名字
    double Stu_ID[12];     //学号
    struct grade        //成绩        
    {
        float NUM[6];
    }Grade;
    
}InFor;

InFor student [MAX_Student_Num];             //最大班级人数
InFor people [31];       //班级人数                 

int main(){             //主要完成选择任务栏
    int Math;
    Print_Menu();
    while(1)
    {
        scanf("%d",&Math);
        switch (Math)
		    {
		    case 1:
		    	system("cls");  
                InputStu_Infor();
                system("cls");
                Print_Menu();
                break;
    
		    case 2:
		    	system("cls");  
                Cal_Course_V();
                Return_Menu();
                system("cls");
                Print_Menu();
                break;
		    case 3:
		    	system("cls");  
                Cal_Stu_V();
                Return_Menu();
                system("cls");
                Print_Menu();
		    	break;
		    case 4:
		    	system("cls"); 
                High_Short();
                system("cls");
                Print_Menu(); 
		    	break;
		    case 5:
		    	system("cls");  
                Short_High();
                system("cls");
                Print_Menu(); 
		    	break;
		    case 6:
		    	system("cls");
                Stu_ID_Order();
                system("cls");
                Print_Menu();  
		    	break;
		    case 7:
		    	system("cls"); 
                Name_Dic(); 
                system("cls");
                Print_Menu();  
		    	break;
		    case 8:
		    	system("cls"); 
                FindStu_ID();
                system("cls");
                Print_Menu();  
		    	break;
		    case 9:
		    	system("cls"); 
                FindName(); 
                system("cls");
                Print_Menu();  
		    	break;
		    case 10:
		    	system("cls");  
                Print_Level();
                Return_Menu();
                system("cls");
                Print_Menu();
		    	break;
		    case 11:
		    	system("cls");
                Print_All(); 
                system("cls");
                Print_Menu();   
		    	break;
		    case 12:
		    	system("cls");  
                Write_File();
                system("cls");
                Print_Menu(); 
		    	break;
		    case 13:
		    	system("cls");  
		    	break;
		    case 0:
		    	system("cls");  
		    	printf("\n\n\n");
		    	printf("\t\t\t******************************************************************************\n");
		    	printf("\t\t\tEnd of program!\n");
		    	printf("\t\t\t******************************************************************************\n");
		    	return 0;
		    default:                //输入有误提醒
		    	system("cls");  
		    	printf("\n\n\n");
		    	printf("\t\t\t******************************************************************************\n");
		    	printf("\t\t\tWarning Error !!!\n");
                printf("\t\t\tPlease input according to the serial numbers from 1 to 13 above!!!\n");
		    	printf("\t\t\t******************************************************************************\n");
		}
    }  
	}

void Print_Menu()               //打印菜单栏
{
    printf("\n");
    printf("\t\t\t******************************************************************************\n");
	printf("\t\t\t*                Management for Students' scores                             *\n");
	printf("\t\t\t*                1.  Input record                                            *\n");
	printf("\t\t\t*                2.  Caculate total and average score of every course        *\n");
	printf("\t\t\t*                3.  Caculate total and average score of every student       *\n");
	printf("\t\t\t*                4.  Sort in descending order by score                       *\n");
	printf("\t\t\t*                5.  Sort in ascending order by score                        *\n");
	printf("\t\t\t*                6.  Sort in ascending order by number                       *\n");
	printf("\t\t\t*                7.  Sort in dictionary order by name                        *\n");
	printf("\t\t\t*                8.  Search by number                                        *\n");
	printf("\t\t\t*                9.  Search by name                                          *\n");
	printf("\t\t\t*                10. Statistic analysis                                      *\n");
	printf("\t\t\t*                11. List record                                             *\n");
	printf("\t\t\t*                12. Write to a file                                         *\n");
	printf("\t\t\t*                13. Read from a file                                        *\n");
	printf("\t\t\t*                0.  Exit                                                    *\n");
	printf("\t\t\t******************************************************************************\n");
    printf("\n");
    printf("\t\t\tPlease input the number for your choice:");
}

void Return_Menu()              //返回菜单栏函数
{
    char input;
        New:
            printf("If you want to quit,Please input ' r' or ' R':");       //如果输入无反应可以尝试在r前加一个空格
            scanf(" %c",&input);
       
            while(1){
       
                if(input == 'r' || input == 'R'){
                    break;
                    }
                    else
                    printf("Error!!!\n");                       //完备性检查，以防他人输错退出指令
                    goto New;
                }
}

void InputStu_Infor()           //输入学生信息
{
    
InFor* p_ID = 0;
InFor* p_Gra = 0;
InFor* p_name = 0;
    p_name = people;
    p_ID = people;
    p_Gra = people; 

    printf("Please enter the number of people in the class:");
    scanf("%d",&Num_class);
    printf("Please enter the total number of subjects for the exam:");
    scanf("%d",&Num_course);

    for (int i = 0; i < Num_class; i++)
    {
        printf("Please input Name:\n");
        scanf("%s",people[i].name);

        printf("Please intput Student ID(The Max Number is 12):\n");
        scanf("%lf",people[i].Stu_ID);
        
        printf("Please intput Student Grade:\n");        
        for(int k = 0;k < Num_course;k++){
            scanf("%f",&people[i].Grade.NUM[k]);
            }

    }
    
    printf("Name        StudentID               Grade\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%s      %.0lf          ",(p_name -> name),*(p_ID -> Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1f",people[i].Grade.NUM[k]);
                printf("\t");
            }
        p_name++;
        p_ID++;
        p_Gra++;

        printf("\n");
    }
        while(getchar() != '\n');
        Return_Menu();
        
}

void Cal_Course_V()       //计算每门课的总分和平均分
{
    float sum[6] = {0};
    for(int i = 0; i < Num_course; i++){
        
        for (int j = 0; j < Num_class; j++)
        {
            sum[i] += people[j].Grade.NUM[i];
        }
        
    }
    for (int k = 0; k < Num_course; k++)
        {
        printf("The Class Sum Grade Is:%.2f\n",sum[k]);
        printf("The Class Average Grade Of %d Is:%.2f\n",k,sum[k]/Num_class);
        }
        
}
    
void Cal_Stu_V()        //计算每个人的总分和平均分
{
    float sum[31] = {0};
    for(int i = 0; i < Num_class; i++){
        for (int j = 0; j < Num_course; j++)
        {
            sum[i] += people[i].Grade.NUM[j];
        }
        
    }

    for (int i = 0; i < Num_class; i++)
    {        
        printf("The Grade Of Student(%s) All Grade Is:%.2f\n",people[i].name,sum[i]);
        printf("The Grade Of Every Student(%s) Is:%.2f\n",people[i].name,sum[i]/Num_course);
        printf("\n");
    }
    
}

void High_Short()           //使用冒泡排序实现(高到低排序并且输出)
{
    float Sum[31]={0};


    for (int i = 0; i < Num_class; i++)
    {
        for (int j = 0; j < Num_course; j++)
        {
            Sum [i] += people[i].Grade.NUM[j];
        }
    }
    for (int i = 0; i < Num_class - 1; i++)
    {
        for (int j = 0; j < Num_class - i - 1; j++)
        {
            if(Sum[j] < Sum[j+1])
            {
                InFor people_t = people[j];
                people[j] = people[j+1];
                people[j+1] = people_t;

                float temp = Sum[j];
                Sum[j] = Sum[j + 1];
                Sum[j + 1] = temp;
            }
        }
        
    }
    printf("\n\n\n");
    printf("The following are the results sorted from highest to lowest based on the total score:\n");
    
    printf("    Name        StudentID               Grade\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1lf",people[i].Grade.NUM[k]);
                printf("\t");
            }

        printf("\n");
    }
        while(getchar() != '\n');
        Return_Menu();
        
    
    
}

void Short_High()           //冒泡排序实现（低到高排序并且输出）
{
float Sum[31]={0};          


    for (int i = 0; i < Num_class; i++)
    {
        for (int j = 0; j < Num_course; j++)
        {
            Sum [i] += people[i].Grade.NUM[j];
        }
    }
    for (int i = 0; i < Num_class - 1; i++)
    {
        for (int j = 0; j < Num_class - i - 1; j++)
        {
            if(Sum[j] > Sum[j+1])
            {
                InFor people_t = people[j];
                people[j] = people[j+1];
                people[j+1] = people_t;

                float temp = Sum[j];
                Sum[j] = Sum[j + 1];
                Sum[j + 1] = temp;
            }
        }
        
    }
    printf("\n\n\n");
    printf("The following are the results sorted from shortest to highest based on the total score:\n");
    
    printf("    Name        StudentID               Grade\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1lf",people[i].Grade.NUM[k]);
                printf("\t");
            }

        printf("\n");
    }
        while(getchar() != '\n');
        Return_Menu();
}

void Stu_ID_Order()         //以学号的大小进行排序（由小到大）          //注：学号在这里默认是相同位数，故没考虑位数不同的情况
{
    
    for (int i = 0; i < Num_class - 1; i++)
    {
        for (int k = 0; k < Num_class - 1 - i; k++)
        {
            for (int j = 0; j < 12; j++)
            {
                if (people[k].Stu_ID[j] > people[k+1].Stu_ID[j]) 
                {
                    InFor Temp = people[k];
                    people[k] = people[k+1];
                    people[k+1] = Temp;
            
                }
            }
        }
    }
    printf("\n\n\n");
    printf("The following are the results sorted from shortest to highest based on the student ID:\n");
    
    printf("    Name        StudentID               Grade\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1lf",people[i].Grade.NUM[k]);
                printf("\t");
            }

        printf("\n");
    }
        while(getchar() != '\n');
        Return_Menu();

}
                                                    
void Name_Dic()             //完成以字典顺序排序        //strcmp函数的应用！！！
{
    for (int i = 0; i < Num_class - 1; i++)
    {
        for (int j = 0; j < Num_class - 1 - i; j++)
        {
            int min_length = strlen(people[j].name) < strlen(people[j+1].name) ? strlen(people[j].name) : strlen(people[j+1].name);
            for (int k = 0; k < min_length; k++)
            {
                if(strcmp(people[j].name, people[j+1].name) > 0)
                {
                    InFor temp = people[j];
                    people[j] = people[j+1];
                    people[j+1] = temp;
                }
            }  
        }
            
    }

    printf("\n\n\n");
    printf("The following are the results sorted from shortest to highest based on the dictionary order:\n");
    
    printf("    Name        StudentID               Grade\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1lf",people[i].Grade.NUM[k]);
                printf("\t");
            }

        printf("\n");
    }
        while(getchar() != '\n');
        Return_Menu();

}

void FindStu_ID()           //按照学号查找信息
{
    double Id[12] = {0};
    int n = 0;
    printf("Please input the student ID to find the information of student:");
    scanf("%lf",Id);

    for (int i = 0; i < Num_class; i++)
    {
        if(*Id == *(people[i].Stu_ID))
        {
            n = i;
        }
    }
    
    printf("%d  %s      %.0lf",n+1,people[n].name,*(people[n].Stu_ID));
    for (int i = 0; i < Num_course; i++)
    {
        printf("        %.1lf",people[n].Grade.NUM[i]);
        printf("\t");
    }
    printf("\n");

    while(getchar() != '\n');
    Return_Menu();
}

void FindName()                 //按照名字查找信息
{
    char name[25];
    int n = 0;
    printf("Please input the student name:");
    scanf("%s",name);
    
    for (int i = 0; i < Num_class; i++)
    {
        if(strcmp(name,people[i].name) == 0)
        {
            n = i;
        }
    }
    printf("%d  %s      %.0lf",n+1,people[n].name,*(people[n].Stu_ID));
    for (int i = 0; i < Num_course; i++)
    {
        printf("        %.1lf",people[n].Grade.NUM[i]);
        printf("\t");
    }
    printf("\n");

    while(getchar() != '\n');
    Return_Menu();
        
}

void Print_Level()              //按照成绩划分优秀...
{
    float sum[31] = {0},aver[31] = {0};
    int a = 0,b = 0,c = 0,d = 0,e = 0;                              //代表五个程度
    
    for(int i = 0; i < Num_class; i++){
        for (int j = 0; j < Num_course; j++)
        {
            sum[i] += people[i].Grade.NUM[j];
            aver[i] = sum[i]/Num_course;        //计算每个人的平均分数
        }
    }

    for (int i = 0; i < Num_class; i++)
    {
        if (aver[i] <= 100 && aver[i] >= 90)
        {
            a++;
        }
        else if(aver[i] <= 89 && aver[i] >= 80)
        b++;
        else if(aver[i] <= 79 && aver[i] >= 70)
        c++;
        else if(aver[i] <= 69 && aver[i] >= 60)   
        d++;
        else
        e++;
    }

    printf("优秀: %d    %.4f\n",a,(float)a/Num_class);
    printf("良好: %d    %.4f\n",b,(float)b/Num_class);
    printf("中等: %d    %.4f\n",c,(float)c/Num_class);
    printf("及格: %d    %.4f\n",d,(float)d/Num_class);
    printf("不及格: %d    %.4f\n",e,(float)e/Num_class);
    
}

void Print_All()                //打印所有已知信息
{
    float sum[31] = {0};
    for(int i = 0; i < Num_class; i++){
        for (int j = 0; j < Num_course; j++)
        {
            sum[i] += people[i].Grade.NUM[j];
        }
    }                           //计算每个人的总成绩、平均分数

    float Sum[6] = {0};
    for(int i = 0; i < Num_course; i++){
        
        for (int j = 0; j < Num_class; j++)
        {
            Sum[i] += people[j].Grade.NUM[i];
        }
        
    }

    printf("    Name        StudentID               Grade       Sum     Average\n");
    for (int i = 0; i < Num_class; i++)
    {

        printf("%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                printf("%.1lf   ",people[i].Grade.NUM[k]);
                printf("\t");
            }
            printf("%.2f    %.2f",sum[i],sum[i]/Num_course);

        printf("\n");
    }
    for (int k = 0; k < Num_course; k++)
    {
        printf("The Class Sum Grade Is:%.2f\n",Sum[k]);
        printf("The Class Average Grade Of %d Is:%.2f\n",k,Sum[k]/Num_class);
    }
    
        while(getchar() != '\n');
        Return_Menu();
    
    
}

void Write_File()               //将已知信息写入文件中
{
    float sum[31] = {0};                                //信息读取
    for(int i = 0; i < Num_class; i++){
        for (int j = 0; j < Num_course; j++)
        {
            sum[i] += people[i].Grade.NUM[j];
        }
    }                           

    float Sum[6] = {0};
    for(int i = 0; i < Num_course; i++){
        
        for (int j = 0; j < Num_class; j++)
        {
            Sum[i] += people[j].Grade.NUM[i];
        }
        
    }                                                   //读取完毕
                                       
    FILE* fp = fopen("students.txt", "w");            // 打开文件
    if (fp == NULL) {
    fprintf(fp,"Failed to open file.\n");
    }
    fprintf(fp,"    Name        StudentID               Grade       Sum     Average\n");
    for (int i = 0; i < Num_class; i++)
    {

        fprintf(fp,"%d  %s      %.0lf          ",i+1,people[i].name,*(people[i].Stu_ID));
            for (int k = 0; k < Num_course; k++)
            {
                fprintf(fp,"%.1lf   ",people[i].Grade.NUM[k]);
                fprintf(fp,"\t");
            }
            fprintf(fp,"%.2f    %.2f",sum[i],sum[i]/Num_course);

        fprintf(fp,"\n");
    }
    for (int k = 0; k < Num_course; k++)
    {
        printf("The Class Sum Grade Is:%.2f\n",Sum[k]);
        printf("The Class Average Grade Of %d Is:%.2f\n",k,Sum[k]/Num_class);
    }
    
    
  

  
  fclose(fp);                                               // 关闭文件
}

void Read_File()                //读取文件夹中的数据
{
    char filename[256];
  printf("Enter filename: ");
  scanf("%s", filename);

  FILE* fp = fopen(filename, "r");
  if (fp == NULL) {
    printf("Failed to open file: %s\n", filename);
    exit(1);
  }

  char line[256];
  while (fgets(line, 256, fp) != NULL) {
    int id;
    char name[256];
    double score;
 
    int ret = sscanf(line, "%d\t%s\t%lf", &id, name, &score);               // 使用sscanf函数从字符串中读取学生记录信息
    if (ret != 3) {
      printf("Failed to parse line: %s", line);
    } 
    else {
                                     // 显示学生记录信息
      printf("Name: %s\n", name);
      printf("Student ID: %d\n", id);
      printf("Score: %.2lf\n", score);
      printf("\n");
    }
  }

  fclose(fp);

  printf("Done.\n");

}