xueji/step3

#include<stdio.h>
struct Student
{
	int id;
	float gs;
	float dw;
	float yy;
	float sum;
	float aver;
}stu[3],temp;
int main()
{
	printf("                              1.Input\n");
	printf("                              2.Output\n");
	printf("                              3.Order\n");
	printf("                              4.Quit\n");
	int i=0,j=0;
	char x;
	scanf("%c",&x);
	switch(x){
		case 'o':printf("You are trying to Output info");break;
		case 'm':printf("You are trying to Make things ordered");break;
		case 'q':printf("You are about to Quit");break;
		case 'i':printf("Please input info of the three students:\n");
			for(i=0;i<3;i++)
			{
				scanf("%d\n",&stu[i].id);
				scanf("%f\n",&stu[i].gs);
				scanf("%f\n",&stu[i].dw);
				scanf("%f\n",&stu[i].yy);
				stu[i].sum=stu[i].gs+stu[i].dw+stu[i].yy;
				stu[i].aver=stu[i].sum/3;
			}
			for( i=0;i<3;i++)//排序操作 
			{
				for( j=0;j<3-i-1;j++)
				{
					if(stu[j].sum>stu[j+1].sum)
					{
					temp=*(stu+j);
					*(stu+j)=*(stu+j+1);
					*(stu+j+1)=temp;
				    }
				}
			}
			for(i=0;i<3;i++)
			{
				printf("学号 %d，总成绩 %.1f,平均成绩 %.1f\n",stu[i].id,stu[i].sum,stu[i].aver);
			}
			break;
			
		default:printf("Wrong input\n");break;
	}
	return 0;
}