编程

#include "stdio.h"
struct stu{
	int sid,score;
	char g;
};
void scorein(struct stu *p,int n){
	int i,t;
	for(i=0;i		scanf("%d%d",&p[i].sid,&p[i].score);
		p[i].g = (t=p[i].score)>89 && t<101 ? 'A' : t>79 && t<90 ? 'B' : t>69 && t<80 ? 'C' : t>59 && t<70 ? 'D' : 'E';
	}
}
int sum(struct stu *p,int n){
	int s=0;
	while(n--)
		s+=p++->score;
	return s;
}
void dssort(struct stu *p,int n){
	int i,j,k;
	struct stu t;
	printf("
STUID	SCORE	CLASS
=====================
");
	for(i=0;i		for(k=i,j=k+1;j			if(p[k].score				k=j;
		if(k!=i)
			t=p[k],p[k]=p[i],p[i]=t;
		printf("%d	%d	%c
",p[i].sid,p[i].score,p[i].g);
	}
}
void idsort(struct stu *p,int n){
	int i,j,k;
	struct stu t;
	printf("
STUID	SCORE	CLASS
=====================
");
	for(i=0;i		for(k=i,j=k+1;j			if(p[k].sid>p[j].sid)
				k=j;
		if(k!=i)
			t=p[k],p[k]=p[i],p[i]=t;
		printf("%d	%d	%c
",p[i].sid,p[i].score,p[i].g);
	}
}
void query(struct stu *p,int n){
	int id;
	printf("
Please enter ID(int)...
");
	scanf("%d",&id);
	while(id-p->sid && n)
		p++,n--;
	if(n>=0){
		printf("STUID	SCORE	CLASS
=====================
");
		printf("%d	%d	%c

",p->sid,p->score,p->g);
	}
	else
		printf("No find!

");
}
void level(struct stu *p,int n){
	int d[5],i;
	char s[5][7]={"优秀","良好","中等","及格","不及格"};
	printf("统计信息如下:
");
	for(i=0;i<5;d[i++]=0);
	for(i=0;ig-'A']++);
	for(i=0;i<5;i++)
		printf("%6s:	%d	%.2f%%
",s[i],d[i],d[i]/(n+0.0)*100);
}
void outinfo(struct stu *p,int n){
	int i;
	printf("
STUID	SCORE
=============
");
	for(i=0;i		printf("%d	%d
",p[i].sid,p[i].score);
}
int main(int argc,char *argv[]){
	int n,s;
	struct stu a[30];
	printf("Please enter n(int 0	if(scanf("%d",&n)!=1 || n<1 || n>30){
		printf("Input error, exit...
");
		return 0;
	}
	scorein(a,n);//输入
	dssort(a,n);//分数降序
	idsort(a,n);//学号升序
	query(a,n);//查询
	level(a,n);//等级和百分比
	outinfo(a,n);//输出各位信息
	printf("总分: %d",s=sum(a,n));
	printf("   平均分:   %.2f
",s/(n+0.0));
	return 0;
}

运行样例：