Problem:
Distance

Write a program which calculates the distance between two points P1(x1, y1) and P2(x2, y2).

Input

Four real numbers x1, y1, x2 and y2 are given in a line.

Output

Print the distance in real number. The output should not contain an absolute error greater than 10-4.

Sample Input

0 0 1 1

Sample Output

1.41421356

Solution in C (judge verdict: Accepted)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>

int main(){
  double x1,y1,x2,y2,nijou,ans=0.0;
  int i;
  scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2);
  nijou=pow((x1-x2),2) + pow((y1-y2),2);
  for(i=0;i<=5;i++){
    while(1){
      if(pow(ans+pow(10,-i),2) <=nijou){
        ans+=pow(10,-i);
      }
      else break;
    }
  }
  printf("%lf\n",ans);
  return 0;
}