学生成绩管理系统

思路

学生成绩管理系统，首先要初始化系统，开始一个新的学生成绩系统初始化记录学生姓名，学号，院系，然后输入学生各科成绩，数学，英语，语文成绩。记录完各课成绩以后，可查看学生平均成绩和是否及格，成绩查询其中有学号查询，姓名查询，院系查询，还有全部输出，可以清晰的看到及格人数，按照分数高低排列，最后还可以添加和删除学生成绩，或者更改学生成绩，避免人为录入成绩错误。

基本函数

1.结构体 struct Student

定义一个结构体struct ，结构体的关键字，students 定义的结构体对象。学号char ID[20];姓名char Name[10]; 各项成绩float Mark，总成绩 float All  平均成绩 float Average;

2.录入（void inputt（））

利用循环将数据从students[0]开始录入各项信息，计数器num+1。

2.删除（void deletee（））

利用循环将数组里面的信息与待删除的信息比对，若相同，将此项删除并将后面的信息向前移动一位，计数器num-1；若无此项，提示重新输入。

3.修改（void modfiy（））

利用循环将数组里面的信息与待修改的信息比对，若相同，对其进行重新复制即修改；若无此项，提示重新输入。

4.插入（void insert（）)

提示输入插入的位置，将该位置后及该位置的信息向后挪一位，将新信息录入该位置。计数器num+1。

5.排序 （void sort（））

走排序的平均分，依次比较两个相邻的成绩，如果他们的顺序如果前小于后就把他们交换过来。走访元素的工作是重复地进行直到没有相邻元素需要交换，也就是说该元素已经排序完成。

6.显示 （void display（））

利用循环将已录入的信息打印出来。

7.查询 （void Student_SearchByIndex（））

提示要查询学生的学号，利用循环比对，若相同，将此项信息打印出来；若无此项，提示重新输入。

8.主函数 main（）

利用无限次循环while和swithch（)实现各函数的调用，系统根据输入的数字来操控相应的函数，同时显示可供选择的选项。

#include<stdio.h>#include<stdlib.h>#include<stdlib.h>#include<string.h>struct Student{   //每个学生对应一个结构体 char ID[20];//学号 char Name[10];//姓名 float Mark1;//语文成绩 float Mark2;//数学成绩 float Mark3;//英语成绩 float Mark4;//计算机成绩 float All; //总分 float Average;//平均成绩 }students[1000];int num=0; //计数器void Copy(struct Student *arr,int i,int j){strcpy(arr[i].ID,arr[j].ID);strcpy(arr[i].Name,arr[j].Name);arr[i].Mark1 = arr[j].Mark1;arr[i].Mark2 = arr[j].Mark2;arr[i].Mark3 = arr[j].Mark3;arr[i].Mark4 = arr[j].Mark4;arr[i].All = arr[j].All;arr[i].Average = arr[j].Average;}int Student_SearchByName(char name[])//通过姓名来检索学生{     int i;     for (i=0;i<num;i++)     {         if (strcmp(students[i].Name,name)==0)  //通过strcmp函数来对比学生姓名，找到返回在数组的位置          {              return i;       }     }     return -1;    //未找到返回 -1 }int Student_SearchByIndex(char id[])//通过学号来检索学生信息{     int i;     for (i=0;i<num;i++)     {         if (strcmp(students[i].ID,id)==0)  //通过strcmp函数来对比学生id，找到返回位置          {              return i;         }       }     return -1;   //未找到返回 -1 }void Student_DisplaySingle(int index)//输出表头{     printf("%10s%10s%8s%8s%8s%10s\n","学号","姓名","语文","数学","英语","计算机","总成绩","平均成绩");     printf("-------------------------------------------------------------\n");     printf("%10s%10s%8.2f%8.2f%8.2f%8.2f%10.2f%10.2f\n",students[index].ID,students[index].Name,              students[index].Mark1,students[index].Mark2,students[index].Mark3,students[index].Mark4,students[index].All,students[index].Average);}void inputt()//利用循环录入学生信息{     while(1)     {         printf("请输入学号:");         scanf("%s",&students[num].ID);         getchar();         printf("请输入姓名:");         scanf("%s",&students[num].Name);         getchar();         printf("请输入成绩:");         scanf("%f",&students[num].Mark1);         getchar();         printf("请输入成绩:");         scanf("%f",&students[num].Mark2);         getchar();         printf("请输入成绩:");         scanf("%f",&students[num].Mark3);         getchar();         printf("请输入成绩:");         scanf("%f",&students[num].Mark4);   //依次输入各项数据          getchar();         students[num].All=students[num].Mark1+students[num].Mark2+students[num].Mark3+students[num].Mark4;    //输完数据后自动计算总成绩与平均成绩          students[num].Average=(students[num].Mark1+students[num].Mark2+students[num].Mark3+students[num].Mark4)/4;         if(Student_SearchByIndex(students[num].ID) == -1)         {         num++;  //移向下一个位置  } else { printf("学号重复，输入数据无效 !!!\n"); }   printf("是否继续?(y/n)");         if (getchar()=='n')         {              break;         }     }}void modify()//修改成绩{  while(1)     {         char id[20];         int index;         printf("请输入要修改的学生的学号:");         scanf("%s",&id);         getchar();         index=Student_SearchByIndex(id);  //调用搜查id函数，根据其返回值确定位置          if (index==-1)         {              printf("学生不存在!\n");         }         else         {              printf("你要修改的学生信息为:\n");              Student_DisplaySingle(index);              printf("-- 请输入新值--\n");              printf("请输入学号:");              scanf("%s",&students[index].ID);              getchar();              printf("请输入姓名:");              scanf("%s",&students[index].Name);              getchar();              printf("请输入语文成绩:");              scanf("%f",&students[index].Mark1);   getchar();              printf("请输入数学成绩:");              scanf("%f",&students[index].Mark2);              getchar();              printf("请输入英语成绩:");              scanf("%f",&students[index].Mark3);              getchar();              printf("请输入计算机成绩:");              scanf("%f",&students[index].Mark4);  //重新录入一套新的数据替代               getchar();              students[index].All=students[index].Mark1+students[index].Mark2+students[index].Mark3+students[index].Mark4;          students[index].Average=(students[index].Mark1+students[index].Mark2+students[index].Mark3+students[index].Mark4)/4;            }         printf("是否继续?(y/n)");         if (getchar()=='n')         {              break;         }     }}void deletee()//删除学生信息{  int i;     while(1)     {         char id[20];         int index;         printf("请输入要删除的学生的学号:");         scanf("%s",&id);         getchar();         index=Student_SearchByIndex(id);   //调用搜查id函数，根据其返回值确定位置          if (index==-1)         {              printf("学生不存在!\n");         }         else         {              printf("你要删除的学生信息为:\n");              Student_DisplaySingle(index);              printf("是否真的要删除?(y/n)");              if (getchar()=='y')              {                   for (i=index;i<num-1;i++)                   {                      Copy(students,i,i+1);                       //students[i]=students[i+1];    //把后边的对象都向前移动                   }                   num--;              }             getchar();         }         printf("是否继续?(y/n)");         if (getchar()=='n')         {              break;         }     }}void display()//打印已录入的学生信息{ int a;     printf("%10s%10s%8s%8s%8s%8s%10s%10s\n","学号","姓名","语文","数学","英语","计算机","总成绩","平均成绩");     printf("-------------------------------------------------------------\n");     for (a=0;a<num;a++)     {         printf("%10s%10s%8.2f%8.2f%8.2f%8.2f%10.2f%10.2f\n",students[a].ID,students[a].Name,              students[a].Mark1,students[a].Mark2,students[a].Mark3,students[a].Mark4,students[a].All,students[a].Average);     }}void insert()//指定位置插入学生信息{int a,b,c;printf("请输入你要插入的位置");scanf("%d",&a);if(a>num) {printf("输入的位置有误，请重新输入,当前共%d条数据\n",num); scanf("%d",&a);}      b=num-1;     for(;b>=a-1;b--)     {     //strcpy(students[b+1].ID,students[b].ID);     //strcpy(students[b+1].Name,students[b].Name);     //students[b+1].Mark1=students[b].Mark1;     //students[b+1].Mark2=students[b].Mark2;     //students[b+1].Mark3=students[b].Mark3;     //students[b+1].Mark4=students[b].Mark4;     //students[b+1].All=students[b].All;     //students[b+1].Average=students[b].Average;  Copy(students,b+1,b); //根据其输入的位置，将其及以后的数据向后移动一个位置       } num++;         printf("请输入学号:");         scanf("%s",&students[a-1].ID);         getchar();         printf("请输入姓名:");         scanf("%s",&students[a-1].Name);         getchar();         printf("请输入语文成绩:");         scanf("%f",&students[a-1].Mark1);         getchar();         printf("请输入数学成绩:");         scanf("%f",&students[a-1].Mark2);         getchar();         printf("请输入英语成绩:");         scanf("%f",&students[a-1].Mark3);         getchar();         printf("请输入计算机成绩:");         scanf("%f",&students[a-1].Mark4);  //输入新数据          getchar();           students[a-1].All=students[a-1].Mark1+students[a-1].Mark2+students[a-1].Mark3+students[a-1].Mark4;         students[a-1].Average=(students[a-1].Mark1+students[a-1].Mark2+students[a-1].Mark3+students[a-1].Mark4)/4; }void search()//查询学生信息{ while(1)     {         char name[20];         int index;         printf("请输入要查询的学生的姓名:");         scanf("%s",&name);         getchar();         index=Student_SearchByName(name);   //调用搜查name函数，根据其返回值确定位置          if (index==-1)         {              printf("学生不存在!\n");         }         else         {              printf("你要查询的学生信息为:\n");              Student_DisplaySingle(index);         }         printf("是否继续?(y/n)");         if (getchar()=='n')         {              break;         }     }}void sort()//根据平均分排序{ int i,j; //struct students tmp;     for (i=0;i<num;i++)     {     students[i].Average=(students[i].Mark1+students[i].Mark2+students[i].Mark3+students[i].Mark4)/4;     }     for (i=0;i<num;i++)     {         for (j=1;j<num-i;j++)         {              if (students[j-1].Average<students[j].Average)              {                     Copy(students,num,j-1);   Copy(students,j-1,j);   Copy(students,j,num);    //tmp=students[j-1];                   //students[j-1]=students[j];                   //students[j]=tmp;      //冒泡排序             }           }     }     int a;     printf("%10s%10s%8s%8s%8s%10s\n","学号","姓名","语文","数学","英语","计算机","总成绩","平均成绩");     printf("-------------------------------------------------------------\n");     for (a=0;a<num;a++)     {         printf("%10s%10s%8.2f%8.2f%8.2f%8.2f%10.2f%10.2f\n",students[a].ID,students[a].Name,              students[a].Mark1,students[a].Mark2,students[a].Mark3,students[a].Mark4,students[a].All,students[a].Average);     }}   void SearchLow()//搜索不及格的并输出 {int a;printf("           语文不及格的有%10s%10s%8s\n","学号","姓名","语文"); for(a=0;a<num;a++){ if(students[a].Mark1<60)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark1);    //从头搜索到尾，若小于60就输出  }  printf("           数学不及格的有%10s%10s%8s\n","学号","姓名","数学"); for(a=0;a<num;a++){ if(students[a].Mark2<60)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark2); }   printf("           英语不及格的有%10s%10s%8s\n","学号","姓名","英语");for(a=0;a<num;a++){ if(students[a].Mark3<60)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark3); }   printf("           计算机不及格的有%10s%10s%8s\n","学号","姓名","计算机");for(a=0;a<num;a++){ if(students[a].Mark4<60)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark4); }  system("pause");} void SearchHigh()//搜索成绩最高者输出 {int a;int max ;printf("           语文最高分为%10s%10s%8s\n","学号","姓名","语文"); max=students[0].Mark1;for(a=1;a<num;a++){ if(students[a].Mark1>max)max=students[a].Mark1;}for(a=0;a<num;a++){ if(max==students[a].Mark1)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark1);}printf("           数学最高分为%10s%10s%8s\n","学号","姓名","数学"); max=students[0].Mark2;for(a=1;a<num;a++){ if(students[a].Mark2>max)max=students[a].Mark2;}for(a=0;a<num;a++){ if(max==students[a].Mark2)printf("%10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark2);}printf("           英语最高分为%10s%10s%8s\n","学号","姓名","英语"); max=students[0].Mark3;for(a=1;a<num;a++){ if(students[a].Mark3>max)max=students[a].Mark3;}for(a=0;a<num;a++){ if(max==students[a].Mark3)printf("           %10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark3);}printf("           计算机最高分为%10s%10s%8s\n","学号","姓名","计算机"); max=students[0].Mark4;for(a=1;a<num;a++){ if(students[a].Mark4>max)max=students[a].Mark4;}for(a=0;a<num;a++){ if(max==students[a].Mark4)printf("           %10s%10s%8.2f\n",students[a].Name,students[a].ID,students[a].Mark4);} system("pause");}void Save(){FILE*fp = fopen("temp.txt","w+");fprintf(fp,"%d\n",num);for(int i = 0 ; i< num ;i++){fprintf(fp,"%s %s %f %f %f %f %f %f\n",students[i].ID,students[i].Name,students[i].Mark1,students[i].Mark2,students[i].Mark3,students[i].Mark4,students[i].All,students[i].Average);}fclose(fp);}void Load(){FILE*fp = fopen("temp.txt","r");fscanf(fp,"%d",&num);for(int i = 0 ; i< num ;i++){fscanf(fp,"%s %s %f %f %f %f %f %f\n",students[i].ID,students[i].Name,&students[i].Mark1,&students[i].Mark2,&students[i].Mark3,&students[i].Mark4,&students[i].All,&students[i].Average);}fclose(fp);} /*主程序*/int main(){int i;while(1){ Load(); printf("\t\t\t\t\t-------- 学生成绩管理系统-------\n\n\n\n");     //菜单          printf("\t\t\t\t\t1. 增加学生记录\n\n");         printf("\t\t\t\t\t2. 修改学生记录\n\n");         printf("\t\t\t\t\t3. 删除学生记录\n\n");         printf("\t\t\t\t\t4. 插入学生记录\n\n");         printf("\t\t\t\t\t5. 显示所有记录\n\n");         printf("\t\t\t\t\t6. 查询学生记录\n\n");         printf("\t\t\t\t\t7. 按平均成绩排序\n\n");         printf("\t\t\t\t\t8. 输出各科目不及格学生\n\n");         printf("\t\t\t\t\t9. 输出各科目最高分\n\n");         printf("\t\t\t\t\t0. 退出\n\n\n");         printf("请选择(0-9):");  scanf("%d",&i);switch(i){ case 1:inputt();break; case 2:modify();break;  case 3:deletee();break;  case 4:insert();break;  case 5:display();break; case 6:search();break; case 7:sort();break; case 8:SearchLow();break; case 9:SearchHigh();break; case 0:exit(0); default:  ;}Save();} return 0; } 

代码进行了以下修改

1.关于含有数组成员的结构体拷贝的问题

2.对学号的唯一，进行了限定(inputt函数)

3.增加了从文件读写

现存问题

1.输出格式

2.插入时（insert）没对学号进行唯一性判断