题解 | 单组_spj判断浮点误差
#include<stdio.h>#define PI 3.141592653589int main(){int r;scanf("%d",&r);double S=rrPI;printf("%lf",S);}
#include<stdio.h> #define PI 3.141592653589 int main() { int r; scanf("%d",&r); double S=r*r*PI; printf("%lf",S); return 0; }