步骤1
int main()
{
    char controll;
    char arr1[] = { "                              1.Input" };
    char arr2[] = { "                              2.Output" };
    char arr3[] = { "                              3.Order" };
    char arr4[] = { "                              4.Quit" };
    char arr5[] = { "You are trying to Input info" };
    char arr6[] = { "You are trying to Output info" };
    char arr7[] = { "You are trying to Make things ordered" };
    char arr8[] = { "You are about to Quit" };
    printf("%s\n%s\n%s\n%s\n", arr1, arr2, arr3, arr4);
    scanf_s("%c", &controll);
    switch (controll) {
    case 'i':printf("\n%s\n", arr5); break;
    case 'o':printf("\n%s\n", arr6); break;
    case 'm':printf("\n%s\n", arr7); break;
    case 'q':printf("\n%s\n", arr8); break;
        default:printf("Wrong input");
    }
   
}
步骤2
#include<stdio.h>
int main()
{
	int num[3];
	float math[3],physic[3],english[3],sum[3];
	int i;
	for(i=0;i<3;i++)
	{
		scanf("%d %f %f %f",&num[i],&math[i],&physic[i],&english[i]);
		sum[i]=math[i]+physic[i]+english[i];
	}
	for(i=0;i<3;i++)
	{
		printf("%d %.1f %.1f %.1f %.1f\n",num[i],math[i],physic[i],english[i],sum[i]);
	}	
}

步骤3
int main()
{
    char controll;
    char arr1[] = { "                              1.Input" };
    char arr2[] = { "                              2.Output" };
    char arr3[] = { "                              3.Order" };
    char arr4[] = { "                              4.Quit" };
    char arr5[] = { "Please input info of the three students:" };
    char arr7[] = { "You are trying to Make things ordered" };
    char arr8[] = { "You are about to Quit" };
    printf("%s\n%s\n%s\n%s\n", arr1, arr2, arr3, arr4);
    scanf_s("%c", &controll);
    switch (controll) {
    case 'i':printf("\n%s\n", arr5); break;
    case 'm':printf("\n%s\n", arr7); break;
    case 'q':printf("\n%s\n", arr8); break;
    default:printf("Wrong input");
    }
            struct student
            {
                int number;
                float gaoshu;
                float dawu;
                float yy;
                float add;
                float aver;
            }student1, student2, student3,studenttemp;
scanf("%d",&student1.number);
scanf("%f",&student1.gaoshu);
scanf("%f",&student1.dawu);
scanf("%f",&student1.yy);
scanf("%d",&student2.number);
scanf("%f",&student2.gaoshu);
scanf("%f",&student2.dawu);
scanf("%f",&student2.yy);
scanf("%d",&student3.number);
scanf("%f",&student3.gaoshu);
scanf("%f",&student3.dawu);
scanf("%f",&student3.yy);
            student1.add = (student1.gaoshu + student1.dawu + student1.yy);
            student2.add = (student2.gaoshu + student2.dawu + student2.yy);
            student3.add = (student3.gaoshu + student3.dawu + student3.yy);
            student1.aver = student1.add / 3;
            student2.aver = student2.add / 3;
            student3.aver = student3.add / 3;
            if (student1.add > student2.add) {
                studenttemp = student1;
                student1 = student2;
                student2 = studenttemp;
         }
            if (student1.add > student3.add) {
                studenttemp = student1;
                student1 = student3;
                student3 = studenttemp;
            }
            if (student2.add > student3.add) {
                studenttemp = student2;
                student2 = student3;
                student3 = studenttemp;
            }
            printf("%d,%.1f,%.1f\n", student1.number, student1.add, student1.aver);
            printf("%d,%.1f,%.1f\n", student2.number, student2.add, student2.aver);
            printf("%d,%.1f,%.1f\n", student3.number, student3.add, student3.aver);
    
   
}
步骤四
#include <stdio.h>
int num[4],cla[4];
float f[4],s[4],t[4],add[4];
int begin,sta;
int n=4;
int insert;
void sort(float add[])
{
	int i,j,te;
	float zh;
	for(i=n-1;i>sta;i--)
	{
		if(add[i]>add[i-1])
		{
			zh=add[i];add[i]=add[i-1];add[i-1]=zh;
			te=num[i];num[i]=num[i-1];num[i-1]=te;
			zh=f[i];f[i]=f[i-1];f[i-1]=zh;
			zh=s[i];s[i]=s[i-1];s[i-1]=zh;
			zh=t[i];t[i]=t[i-1];t[i-1]=zh;
		}
	}
	if(n!=sta+1)
	 {
	sta++; 
	sort(add);}
}

void div(int clas[])
{
	int i,j,te;
	float zh;
	for(i=0;i<n-1;i++)
	{
		if(clas[i]>clas[i+1])
		{
			te=clas[i];clas[i]=clas[i+1];clas[i+1]=te;
			zh=add[i];add[i]=add[i+1];add[i+1]=zh;
			te=num[i];num[i]=num[i+1];num[i+1]=te;
			zh=f[i];f[i]=f[i+1];f[i+1]=zh;
			zh=s[i];s[i]=s[i+1];s[i+1]=zh;
			zh=t[i];t[i]=t[i+1];t[i+1]=zh;
		}
	}
	if(n!=sta+1){
		n--;
	div(clas);}

}
 
int main()
{
void sort(float add[]);
void div(int clas[]);
num[0]=10001;num[1]=10002;num[2]=10003;
cla[0]=11;cla[1]=12;cla[2]=11;
f[0]=99.5;f[1]=77.9;f[2]=92.5;
s[0]=88.5;s[1]=56.5;s[2]=99.0;
t[0]=89.5;t[1]=87.5;t[2]=60.5;
for(int i=0;i<3;i++)
{
	add[i]=f[i]+s[i]+t[i];	
}
scanf("%d",&num[3]);
insert=num[3];
int in=num[3];
for(int i=0;i<3;i++){
	if(in==num[i]){
		printf("%d %d %f %f %f %f",num[i],cla[i],f[i],s[i],t[i],add[i]);
		return 0;
	}
}
scanf("%d",&cla[3]);
scanf("%f",&f[3]);
scanf("%f",&s[3]);
scanf("%f",&t[3]);
add[3]=f[3]+s[3]+t[3];
sta=0;begin=0;
div(cla);
n=4;
int m;
for(m=0;m<n;m++){
	if(cla[m]!=cla[m+1])
		break;
}
sta=m;begin=sta;
sort(add);
n=m+1;
sta=0;begin=sta;
sort(add);
n=4;
for(int j=0;j<n;j++){
	printf("%d %d %f %f %f %f",num[j],cla[j],f[j],s[j],t[j],add[j]);
	if(num[j]==insert) printf(" insert\n");
	else printf("\n");
}

 } 
 步骤五
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int num[4],cla[4];
float f[4],s[4],t[4],add[4];
int begin,sta;
int n=3;
int insert;
char name[4][10]={{"Zhang"},{"Yang"},{"Liang"}};
void sort(float add[])
{
	int i,j,te;
	float zh;
	char oo[10];
	for(i=n-1;i>sta;i--)
	{
		if(add[i]>add[i-1])
		{
			zh=add[i];add[i]=add[i-1];add[i-1]=zh;
			te=num[i];num[i]=num[i-1];num[i-1]=te;
			zh=f[i];f[i]=f[i-1];f[i-1]=zh;
			zh=s[i];s[i]=s[i-1];s[i-1]=zh;
			zh=t[i];t[i]=t[i-1];t[i-1]=zh;
			strcpy(oo,name[i]);strcpy(name[i],name[i-1]);
			strcpy(name[i-1],oo); 
		}
	}
	if(n!=sta+1)
	 {
	sta++; 
	sort(add);}
}

void div(int clas[])
{
	int i,j,te;
	float zh;
	char oo[10];
	for(i=0;i<n-1;i++)
	{
		if(clas[i]>clas[i+1])
		{
			te=clas[i];clas[i]=clas[i+1];clas[i+1]=te;
			zh=add[i];add[i]=add[i+1];add[i+1]=zh;
			te=num[i];num[i]=num[i+1];num[i+1]=te;
			zh=f[i];f[i]=f[i+1];f[i+1]=zh;
			zh=s[i];s[i]=s[i+1];s[i+1]=zh;
			zh=t[i];t[i]=t[i+1];t[i+1]=zh;
			strcpy(oo,name[i]);strcpy(name[i],name[i+1]);
			strcpy(name[i+1],oo); 
		}
	}
	if(n!=sta+1){
		n--;
	div(clas);}

}
 

int main()
{
void sort(float add[]);
void div(int clas[]);
num[0]=10001;num[1]=10002;num[2]=10003;
cla[0]=11;cla[1]=12;cla[2]=11;
f[0]=99.5;f[1]=77.9;f[2]=92.5;
s[0]=88.5;s[1]=56.5;s[2]=99.0;
t[0]=89.5;t[1]=87.5;t[2]=60.5;
sta=0;begin=0;
div(cla);
n=3;
int m;
for(m=0;m<n;m++){
	if(cla[m]!=cla[m+1])
		break;
}
sta=m;begin=sta;
sort(add);
n=m+1;
sta=0;begin=sta;
sort(add);
n=3;
	//scanf("delete");
	printf("请输入要删除的学生信息（学号或姓名）\n");
	scanf("%s",name[3]);
	int exist=0,target;
	if(name[3][0]>='0'&&name[3][0]<='9') 
	{
		int number=atoi(name[3]);
		for(int i=0;i<3;i++){
			if(number==num[i]){
				printf("Are you sure(yes)?\n");
				exist=1;
				target=i;
				break;
			}
		}
	}
	else 
	{
		for(int i=0;i<3;i++){
			if(strcmp(name[i],name[3]));
			else{
				printf("Are you sure(yes)?\n");
				exist=1;
				target=i;
				break;
			}
		}
	}
	char ch;
	if(exist==1){
		scanf(" %c",&ch);
		if(ch=='y'){
			for(int i=0;i<3;i++){
				if(i!=target){
					printf("%d %d %s %.2f %.2f %.2f\n",num[i],cla[i],name[i],f[i],s[i],t[i]);
				}
			}
		}
		if(ch=='n'){
			for(int i=0;i<3;i++){
				printf("%d %d %s %.2f %.2f %.2f\n",num[i],cla[i],name[i],f[i],s[i],t[i]);				
				}		
			}
	}
	else{
		for(int i=0;i<3;i++){
				printf("%d %d %s %.2f %.2f %.2f\n",num[i],cla[i],name[i],f[i],s[i],t[i]);				
		}
	}
	return 0;	
 }
步骤六
#include<stdio.h>
struct Scoreb{
	int schoolnumber;
	int classnumber;
	char name[20];
	float math;
	float physics;
	float english;
	float sum;
};
int main(){ 
struct Scoreb student1={10001,11,"Zhang",99.5,88.5,89.5,277.5};
    struct Scoreb student2={10002,12,"Yang",77.9,56.5,87.5,221.9};
	struct Scoreb student3={10003,11,"Liang",92.5,99.0,60.5,252};	
	struct Scoreb students[3] = {student1,student2,student3};
	
	struct Scoreb schange;
	scanf("%d%d%s%f%f%f",&schange.schoolnumber,&schange.classnumber,&schange.name,&schange.math,&schange.physics,&schange.english);int c=schange.schoolnumber;
	for(int i=0;i<3;i++){
		if(schange.schoolnumber==students[i].schoolnumber){
			schange.sum = schange.math+schange.physics+schange.english;
			students[i]=schange;
		}	
	}

	for(int j = 0 ; j < 3 ; j++)
		for(int k = 2; k > j;k--){
			if(students[k].classnumber <students[k-1].classnumber){
				struct Scoreb temp1 = students[k-1];
				students[k-1] = students[k];
				students[k] = temp1;
			
			}else if(students[k].classnumber == students[k-1].classnumber){
				if(students[k].sum>students[k-1].sum){
				struct Scoreb temp2 = students[k-1];
				students[k-1] = students[k];
				students[k] = temp2;
				}
			}
		}
	 
	for(int i = 0; i < 2 ; i++){
		printf("%d %d %s %.1f %.1f %.1f ",students[i].classnumber,students[i].schoolnumber,students[i].name,students[i].math,students[i].physics,students[i].english);
		if(c==students[i].schoolnumber)
		printf("modified\n");
		if(students[0].classnumber==students[1].classnumber)
		{
		printf("   %d %s %.1f %.1f %.1f\n",students[1].schoolnumber,students[1].name,students[1].math,students[1].physics,students[1].english);break;}
	}
	printf("%d %d %s %.1f %.1f %.1f\n",students[2].classnumber,students[2].schoolnumber,students[2].name,students[2].math,students[2].physics,students[2].english);
	if(c==students[2].schoolnumber)
	printf(" modified");
	return 0; 

}

步骤七
#include <stdio.h>
#include <string.h>
struct student
            {
                int number;
                int clas;
                char name[10];
                float grade1;
                float grade2;
                float grade3;
                float sum;
                int signal;
            }student[7]={{10001,11,"Zhang",99.5,88.5,89.5,0,0},
			             {10002,12,"Yang",77.9,56.5,87.5,0,0},
			             {10003,11,"Liang",92.5,99.0,60.5,0,0},
			             {10004,11,"Cai",89.6,56.9,90.5,0,0},
			             {10005,14,"Fu",55.6,67.9,98.9,0,0},
			             {10006,12,"Mao",22.1,45.9,99.2,0,0},
			             {10007,13,"Zhan",35.6,67.9,88.0,0,0}
			            };
struct student temp;


void clas();
void number();
void name();
void grade();
void classandnumber();

const int n=7;
int main()
{
	int identity;
	scanf("%d",&identity);
	for(int i=0;i<7;i++)
	{
		student[i].sum=student[i].grade1+student[i].grade2+student[i].grade3;
	}
    int  i,j,k;
	for(i=0;i<n-1;i++)
	{
		k=i;
		for(j=i+1;j<n;j++)
		{
			if(student[j].clas<student[k].clas)
			{
			    k=j;		
			}
			else if(student[j].clas==student[k].clas)
			{
				if(student[j].sum>student[k].sum)
				{
					k=j;
				}
		    }
		}
		temp=student[k];
		student[k]=student[i];
		student[i]=temp;	
	}	
	switch(identity)
	{
		case 1:clas();break;
		case 2:number();break;
		case 3:name();break;
		case 4:grade();break;
		case 5:classandnumber();break;
		default:printf("Wrong input!\n");
	}		
	for(i=0;i<n;i++)
	{
		if(student[i].signal!=0)
		{
			printf("%6d %3d %8s %6.1f %6.1f %6.1f\n",student[i].number,student[i].clas,student[i].name,student[i].grade1,student[i].grade2,student[i].grade3);
		}
	}
	return 0;
}


void clas()
{
	int inf,noun,sup;
	scanf("%d%c%d",&inf,&noun,&sup);
	printf("%d %d",inf,sup);
	for(int i=0;i<7;i++)
	{
		if(student[i].clas>=inf&&student[i].clas<=sup)
		student[i].signal=1;
	}
}

void number()
{
	int inf,noun,sup;
	scanf("%d%c%d",&inf,&noun,&sup);
	for(int i=0;i<7;i++)
	{
		if(student[i].number>=inf&&student[i].number<=sup)
		student[i].signal=1;
	}
}

void name()
{		    
    int i=0,k,count;
    char initial[10];
	scanf("%s",initial);
	printf("%s\n",initial);
	count=strlen(initial);
	bool flag=true;
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<count-2;j++)
		{
			if(student[i].name[j]!=initial[j])
		        flag=false;
		}
		if(flag)
		{
			student[i].signal=1;
		}	    
	}	
}
		
void grade()
{
	int inf;
	scanf("%d",&inf);
	for(int i=0;i<7;i++)
	{
		if(student[i].sum>=inf)
		student[i].signal=1;
	}
}

void classandnumber()
{
	int clas,noun1,inf,noun2,sup;
	scanf("%d%c%d%c%d",&clas,&noun1,&inf,&noun2,&sup);
	for(int i=0;i<7;i++)
	{
		if(student[i].clas==clas)
		{
			if(student[i].number>=inf&&student[i].number<=sup)
		    student[i].signal=1;
		}	
	}
}
步骤八
#include<stdio.h>
#include<string.h> 
#define N 100

struct stu_info
{
	char num[20];
	char cls[20];
	char name[20];
	float math,physics,english,total;
};

struct stu_info stu[N];
int top=0;

void print_menu()
{
	printf("1.input\n");
	printf("2.delete\n");
	printf("3.select\n");
	printf("4.order\n");
	printf("5.output\n");
	printf("6.quit\n");
	printf("please input your option\n");
}

void print()
{
	int i;
	for(i=0;i<top;i++) printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].math,stu[i].physics,stu[i].english,stu[i].total);
}

void input()
{
	char op[20];
	while(1)
	{
		printf("Id ");
		scanf("%s",stu[top].num);
		printf("class ");
		scanf("%s",&stu[top].cls);
		printf("name ");
		scanf("%s",stu[top].name);
		printf("score1 ");
		scanf("%f",&stu[top].math);
		printf("score2 ");
		scanf("%f",&stu[top].physics);
		printf("score3 ");
		scanf("%f",&stu[top].english);
		stu[top].total=stu[top].math+stu[top].physics+stu[top].english;
		top++;
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void del()
{
	int i,d;
	char key[20],op[20];
	while(1)
	{
		i=0,d=0;
		scanf("%s",key);
		while(i<top)
		{
			if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->name,key)==0)
			{
				d++;top--;
				*(stu+i)=*(stu+i+d);
			}
			else
			{
				*(stu+i)=*(stu+i+d);
				i++;
			}
		}
		print();
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void select()
{
	int i,flag;
	char key[20],op[20];
	while(1)
	{
		flag=0;
		scanf("%s",key);
		for(i=0;i<top;i++)
		{
			if(strcmp((stu+i)->num,key)==0||strcmp((stu+i)->cls,key)==0)
			{
				flag=1;
				printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n",stu[i].num,stu[i].cls,stu[i].name,stu[i].math,stu[i].physics,stu[i].english,stu[i].total);
			}
		}
		if(!flag)
		{
			printf("there is no eligible student\n");
			return;
		}
		printf("continue?\n");
		do{
			scanf("%s",op);
		}while(strcmp(op,"yes")!=0&&strcmp(op,"no")!=0);
		if(strcmp(op,"no")==0) return;
	}
}

void order()
{
	int i,j;
	struct stu_info tmp;
	for(i=0;i<top;i++)
	{
		for(j=0;j<top-i-1;j++)
		{
			if(strcmp((stu+j)->cls,(stu+j+1)->cls)==1||strcmp((stu+j)->cls,(stu+j+1)->cls)==0&&((stu+j)->total<(stu+j+1)->total))
			{
				tmp = *(stu+j);
				*(stu+j) = *(stu+j+1);
				*(stu+j+1) = tmp;
			} 
		}
	}
	print();
	return;
}

int main()
{
	int op;
	while(1)
	{
		print_menu();
		scanf("%d",&op);
		switch(op)
		{
			case(1):
				input();
				break;
			case(2):
				del();
				break;
			case(3):
				select();
				break;
			case(4):
				order();
				break;
			case(5):
				print();
				break;
			case(6):
				return 0;
        }
    }
}