#include <cstdio>
#include <cmath>
using namespace std;
int main()
{
double x1,x2,y1,y2;
while(scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2)==4)
{
double length;
length=sqrt( (x2-x1)*(x2-x1)+(y2-y1)*(y2-y1) );
printf("%lf",length);
}
return 0;
}
楼主,我安装的软件math头文件失效,总是输出-1.000000怎么回事?