语法基础第1讲1

#include <cstdio>//printf,scanf
#include <iostream>//cin,cout
#include <cmath>

using namespace std;

int main()
{
    double a,b,c,d;
    scanf("%lf%lf \n %lf%lf",&a,&b,&c,&d);//scanf处理多行输入可以中间加上 '\n'
    //cin >> a >> b >> c >> d;
    printf("%.4lf",sqrt(pow(c-a,2)+pow(d-b,2)));
    return 0;
}