第三章

#include<iostream>
#include<iomanip>
using namespace std;
#define pi 3.1415926
int main(){
    double r,h,cl,cs,cvz;
    cin>>r>>h;
    cl=2*pi*r;
    cs=pi*r*r;
    cvz=cs*h;
    printf("圆的周长是%.2f\n",cl);
    printf("圆的面积是%.2f\n",cs);
    printf("圆的体积是%.2f\n",cvz);
    return 0;
}

#include<iostream>
using namespace std;

int main(){
    char c;
    cin>>c;
    printf("%c对应的ASCII码是%d\n",c,c);
    return 0;
}

#include<iostream>
using namespace std;


int main(){
    int a,b;
    cin>>a>>b;
    double t1,t2;
    t1=(double)a/(double)b;
    t2=a%b;
    printf("%.2f\n",t1);
    cout<<t2<<endl;
    return 0;
}