#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{
y=1;
}
printf("y=%d\n",y);
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19154525-99e15d337c344accb04156e618f23d84.png)
#include <stdio.h>
int main(void)
{
int count,i,n;
double grade,total;
printf("Enter n:");
scanf("%d",&n);
total=0;
count=0;
for(i=1;i<=n;i++){
printf("Enter grade:",i);
scanf("%lf",&grade);
total=total+grade;
if(grade>60){
count++;
}
}
printf("Grade average=%.2f\n",total/n);
printf("Number of successful=%d\n",count);
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19154558-ec29fa042f904959a661c9ae692bbeab.png)
#include <stdio.h>
int main(void)
{
int blank,digit,letter,other;
char ch;
int i;
blank=digit=letter=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<=' ')
blank++;
else
other++;
}
printf("blank=%d,letter=%d,digit=%d,other=%d\n",blank,letter,digit,other);
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19155310-3ad297fb743f4f2dbc9b217761f23026.png)
#include<stdio.h>
int main(void)
{
int i,year,n;
printf("Enter n:");
scanf("%d",&n);
for(i=1;i<=n;i++){
printf("Enter year:");
scanf("%d",&year);
if((year%4==0&&year%100!=0)||(year%400==0)){
printf("该年是闰年\n");
}
else{
printf("该年不是闰年\n");
}
}
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19155711-2d16e4167f4b4922bf37f4504b229f71.png)
#include<stdio.h>
int main(void)
{
char ch;
printf("enter Level: ");
ch=getchar();
switch(ch){
case 'A':printf("%c 90-100\n",ch);break;
case 'B':printf("%c 80-89\n",ch);break;
case 'C':printf("%c 70-79\n",ch);break;
case 'D':printf("%c 60-69\n",ch);break;
case 'E':printf("%c 0-59\n",ch);break;
default: printf("0\n");
}
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19160651-210fee37f6c7407d862b73a1d39e7226.png)
#include<stdio.h>
int main(void)
{
int choice,i;
double price;
for(i=1;i<=5;i++){
printf("[1]Select apples\n");
printf("[2]Select pears\n");
printf("[3]Select oranges\n");
printf("[4]Select grapes\n");
printf("[0]exit\n");
printf("Enter choice:");
scanf("%d",&choice);
if(choice==0)
break;
switch(choice){
case 1:price=3.00;break;
case 2:price=2.50;break;
case 3:price=4.10;break;
case 4:price=10.20;break;
default:price=0.00;break;
}
printf("price=%0.2f\n",price);
}
return 0;
}
![](//images0.cnblogs.com/blog/571408/201310/19161334-895d2d240e824ada98342bde5df9ff44.png)