acm 2001练习题

**#include <iostream>
#include<algorithm>
#include<math.h>
using namespace std;
int main(int argc, char** argv) {
float a,b,c,d;
float result=0;
while(scanf("%f%f%f%f",&a,&b,&c,&d)!=EOF){
 result=sqrt(pow(a-c,2)+pow(b-d,2));
 printf("%.2f\n",result);
}
 return 0;
}**