阿巴

#include<stdio.h>
main()
{
int x,y,temp;
scanf("%d%d",&x,&y);
printf("x=%d,y=%d\n",x,y);
temp=x;
x=y;
y=temp;
printf("x=%d,y=%d\n",x,y);
}

 

#include<stdio.h>
main()
{float a,b,s;
scanf("%f,%f,&a,&b);
s=a*b;
printf("the area of rectangle is %5.2f\n",s);
}

 

#include<stdic.h>
main()
{
char c1,c2;
scanf("%c".&c1);
printf("the upper case is %c\n",c1);
c2=c1+'a'-'A';
printf("the lower case is %c\n",c2);
}