#include<stdio.h>
int main(void)
{
int x,y;
printf("Enter x:");
scanf("%d",&x);
if(x>0){
y=1;
}
else if(x==0){ y=0;
}
else if(x<0) { y=-1;
}
printf("y=%d",y);
return 0;
}
#include<stdio.h>
int main(void)
{
int count,i,n;
double grade,sum;
printf("Enter n:");
scanf("%d",&n);
sum=0;
count=0;
for(i=1;i<=n;i++){
printf("Enter grade#%d:",i);
scanf("%Lf",&grade);
sum=sum+grade;
if(grade>=60)
count++;
}
printf("平均成绩=%.3f\n",sum/n);
printf("及格人数=%d\n",count);
return 0;
}
#include<stdio.h>
int main(void)
{
int letter,blank,digit,other;
char ch;
int i;
letter=blank=digit=other=0;
printf("Enter 15 characters:");
for(i=1;i<=15;i++){
ch=getchar();
if((ch>='a'&& ch<='z')||(ch>='A'&& ch<='Z'))
letter++;
else if(ch>='0'&&ch<='9')
digit ++;
else if((ch>=' '&&ch<=' ')||(ch>='\n'&&ch<='\n'))
blank++;
else
other++;
}
printf("letter=%d,digit=%d,blank=%d,other=%d\n",letter,digit,blank,other);
return 0;
}
#include<stdio.h>
int main(void)
{
int year,n,i;
printf("Enter n:");
scanf("%d",&n);
for(i=1;i<=n;i++){
printf("Enter year:");
scanf("%d",&year);
if(year==-1)
break;
if((year%4==0&&year%100!=0)||(year%400==0)){
printf("这一年是闰年\n");
}
else
printf("这一年不是闰年\n");
}
return 0;
}
#include<stdio.h>
int main()
{
char ch;
printf("输入成绩等级:");
ch=getchar();
switch(ch){
case 'A':
printf("A对应90-100\n");
break;
case 'B':
printf("B对应80-89\n");
break;
case 'C':
printf("C对应70-79\n");
break;
case 'D':
printf("D对应60-69\n");
break;
case 'E':
printf("E对应0-59\n");
break;
default:
printf("结束\n");
break;
}
return 0;
}
#include<stdio.h>
int main(void)
{
int choice,i;
double price;
for(i=1;i<=5;i++){
printf("[1]apples\n");
printf("[2]pears\n");
printf("[3]oranges\n");
printf("[4]grapes\n");
printf("[0]exit\n");
printf("Enter choice:");
scanf("%d",&choice);
if(choice==0)
break;
switch(choice){
case 1:price=3.0;break;
case 2:price=2.5;break;
case 3:price=4.10;break;
case 4:price=10.20;break;
default:price=0.0;break;
}
printf("price=%.2f\n",price);
}
printf("Thanks\n");
return 0;
}