#include
#define PI 3.14//定义圆周率
int main()
{
float r,L,S;
scanf("%f",&r);
S=PI*r*r;
L=2*PI*r;
printf("S=%.2f\nL=%.2f",S,L);
return 0;
}
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#include
int main()
{
int x,y;
scanf("%d",&x);
if(x<-3)
y=x-2;
if(x>=-3&&x<=3)
y=x*x+3;
if(x>3)
y=7*x;
printf("y=%d",y);
}