NEED HELP!!unable to understand the problem in the code

general
1

I’ve tried hard but I’m not able to find the problem in my code for the problem ‘SEBI AND THE HIGHWAY’.I am getting wrong answer.

PROBLEM:-https://www.codechef.com/problems/SEBIHWY/
my code:-https://www.codechef.com/viewsolution/15035522

2

Firstly, the speed can be decimal, it need not be an integer. You should use double or float for it.

But after doing this, you will get error at if(b==c). Why?

The fact is, if you try to compare two float/double values, you may not get correct answer.

Eg, if i use the code-

double a=3.14,b=3.14;
if(a==b) print("YAY");
else print("Unequal");

It will print unequal, due to way how floating numbers are stored. 3.14 is not stored as 3.14, but as 3.14000001 . or perhaps 3.14000000000001. We dont know, but its clear that its all 0 till 6th decimal place. So instead of equality, we check if the two floating values are same till 6th decimal place.

I.e, instead of if(a==b) we use if(abs(a-b)<=0.000001)

This is one of the errors i noticed in your code. If WA persists, get back to m :slight_smile:

3

Hey,

The problem is with your conversion, since the speed is calculated relative so the actual speed of the other car will be S/3600 + D/(20T) when expressed in km/s. (D50)/(1000) km distance between them and T is in seconds and secondly either you have to use to float or double then only you’ll get correct answer.

Hope this helps! solution for better explanation