功能：查询修改统计成绩。
#include <stdio.h>struct student /*成绩表的结构声明*/{int num;char name[15];char sex;float WuLi;float ShuXue;float YingYu;float KuaiJi;float totle;};/*定义6个学生的信息：*/#define STU_NUMBER 6 /*宏定义学生数为6*/struct student Stu[STU_NUMBER]={{101,"yuchen", 'F', 98,85,96,89,0},{102,"xiaotong", 'F', 99,91,90,93,0},{103,"likanglong",'M', 76,83,74,82,0},{104,"yinger", 'F', 88,76,89,77,0},{105,"fengjiao", 'F', 97,100,94,96,0},{106,"sunyao", 'M', 87,89,66,84,0} };int SelectMainMenu(); /*显示并选择主菜单。
返回：被选择的菜单项*//*所有的函数声明：*/void Show(); /*成绩查询模块*/void Modify(); /*成绩修改模块*/void Stat(); /*成绩统计模块*/void StatAve(float *AveWuLi,float *AveShuXue,float *AveYingYu,float *AveKuaiJi);/*统计平均分*/int FindStudent(int num); /*根据学号查找某一学生*/void SetAllTotle(); /*计算所有学生总分*/void SetTotle(int No); /*计算第No个学生总分*/void ShowAllStudent(); /*显示所有成绩*/void ShowTitle(); /*显示表头信息*/void ShowStudent(int No); /*显示第No个的学生信息*/void main(){int isend=0,password=0; /*程序结束标志量，0表示不结束，1表示结束*/SetAllTotle(); /*计算所有学生总分*/while(password!=666){printf("qing shu ru mi ma:\n");scanf("%d",&password);}{switch(SelectMainMenu()) /*显示并选择主菜单*/{case 1: /*成绩查询*/Show(); /*调用成绩查询函数*/break;case 2: /*成绩修改*/Modify(); /*调用成绩修改函数*/break;case 3: /*成绩统计*/Stat(); /*调用成绩统计函数*/break;case 4: /*退出系统*/printf("\nxie xie nin de shi yong,zai jian！\n\n");isend = 1; /*设置程序结束标志*/break;}if(isend) break; /*程序结束*/}}int SelectMainMenu() /*显示并选择主菜单。
返回：被选择的菜单项*/ {int menu_no=0;do /*显示并选择菜单*/{printf("=================================\n");printf(" <cheng ji guan li cheng xu>\n");printf(" zuo zhe:li yi man\n");printf("=================================\n");printf(" zhu cai dan:\n");printf(" 1 - cheng ji cha xun\n");printf(" 2 - cheng ji xiu gai\n");printf(" 3 - cheng ji tong ji\n");printf(" 4 - tui chu xi tong\n");printf(" qing xuan ze(1-4):");scanf("%d",&menu_no);}while(menu_no<1 && menu_no>4); /*直到选择出正确的序号*/ return menu_no;}void Show() /*成绩查询模块*/{int n,i;{printf("\n====cheng ji cha xun====\n");printf("qing shu ru xue hao(shu ru 0 tui chu cheng ji cha xun,shu ru 1 cha xun quan bu):");scanf("%d",&n);if(n==0) break; /*退出成绩查询模块*/if(n==1) ShowAllStudent(); /*显示所有成绩*/else if((i=FindStudent(n))>=0) /*找到学号为n的学生*/{ShowTitle(); /*显示表头信息*/ShowStudent(i); /*显示该学生信息*/}else printf("----zhao bu dao gai xue hao----\n");}}void Modify() /*成绩修改模块*/{int n,i,a;while(1){printf("\n====cheng ji xiu gai====\n");printf("qing shu ru xue hao(shu ru 0 tui chu cheng ji xiu gai):");scanf("%d",&n);if(n==0)break; /*退出成绩修改模块*/if((i=FindStudent(n))>=0) /*找到学号为n的学生*/{ShowTitle(); /*显示表头信息*/ShowStudent(i); /*显示该学生信息*/printf("qing shu ru yao xiu gai de cheng ji:\n");printf("1 WuLi\n");printf("2 ShuXue\n");printf("3 YingYu\n");printf("4 KuaiJi\n");scanf("%d", &a);switch(a){case 1:printf("qing shu ru WuLi cheng ji:\n");scanf("%f", &Stu[i].WuLi); break;case 2:printf("qing shu ru ShuXue cheng ji:\n");scanf("%f", &Stu[i].ShuXue);break;case 3:printf("qing shu ru YingYu cheng ji:\n");scanf("%f", &Stu[i].YingY u);break;case 4:printf("qing shu ru KuaiJi cheng ji:\n");scanf("%f", &Stu[i].KuaiJi);break;default:printf("shu ru cuo wu");}SetTotle(i); /*计算该学生总分*/printf("----xiu gai cheng gong----\n");}else printf("----zhao bu dao gai xue hao----\n");}}void Stat() /*成绩统计模块*/{float AveWuLi, AveShuXue, AveYingY u, AveKuaiJi;StatAve(&AveWuLi, &AveShuXue, &AveYingYu, &AveKuaiJi); /*统计四门课的班级平均分*/printf("\n====cheng ji tong ji====\n");printf("xue sheng ren shu:%d\n", STU_NUMBER);printf("WuLi ping jun fen:%6.2f\n", AveWuLi);printf("ShuXue ping jun fen:%6.2f\n", AveShuXue);printf("YingYu ping jun fen:%6.2f\n", AveYingYu);printf("KuaiJi ping jun fen:%6.2f\n", AveKuaiJi);}/*统计四门课的班级平均分，用指针参数返回*/void StatAve(float *AveWuLi, float *AveShuXue, float *AveYingYu, float *AveKuaiJi){int i;float sumWuLi=0, sumShuXue=0, sumYingYu=0, sumKuaiJi=0;for(i=0;i<STU_NUMBER;i++){sumWuLi += Stu[i].WuLi;sumShuXue += Stu[i].ShuXue;sumYingY u += Stu[i].YingYu;sumKuaiJi += Stu[i].KuaiJi;}*AveWuLi = sumWuLi / STU_NUMBER;*AveShuXue = sumShuXue / STU_NUMBER;*AveYingYu = sumYingYu / STU_NUMBER;*AveKuaiJi = sumKuaiJi / STU_NUMBER;}/*根据学号查找某一学生。
