Please have a look and tell me where I am going wrong. CodeChef: Practical coding for everyone
@all Alright the question is really interesting a cakewalk that makes you realize that there is difference between real life and computer world;In real world we have infinite precision of floats. But not so in computer I had seen a cs50 video which talks about this 2 months back i didn’t know that it would come this handy though i was not able to find the video you can check this link and this link.The editorial also mentions this part when they say (Be careful: This speed isn’t necessarily an integer). Though the question mentions of converting to double carefully will give AC but i don’t think so moreover the setter’s solution compares distances(integers) rather than speed.Now interesting part about integers is that they are precise.
I hope that this is only the reason ; still trying to get it work the old way as some solutions of others in c work that way.will update this answer soon.
UPDATE: So i was partially correct. check my answer on this question for details. Summary:
Two of the possible mistakes:
1)using division first instead of multiplication and loosing precision.
2)using abs instead of std::abs.(Unintentionally you may end up in using abs defined only for integers; there are two abs() functions check here) using namespace std is important for solutions in c++.ESP if you use <bits/stdc++.h>
.
In c one should use fabs() for this to work.
Best way is to compare distances as in setters solution which are integers and precise.
Please anyone help me out to find the error, it was showing WA CodeChef: Practical coding for everyone
I hope this will answer a some of you getting wrong answer. I had the same problem as most of the guys here. Getting wrong answer when I checked it like a thousand times. Finally during the last half an hour I tried something without any hope of it working but it fetched me AC. What I did was to first check for “DRAW” that is the equals condition rather than “FATHER” or “SEBI” and that is it.
adding a point the answer of @iscsi it is not the matter of float here. As below is @qruiger_116 's solution with using float. Got ac by just changing the expression .so in general float and double are the cause of such problems; it is not so here. Check this out CodeChef: Practical coding for everyone
here the point is that you may lose precisision by dividing first as no. of decimal points is fixed. For more details check the links in my answer below
@hs_123 the distance between the two cars in km can be in decimal, example: 1500 metres=1.5 km. Please read the editorial, it is explicitly mentioned to use typecasting or declare as float or double.Anyway, I changed the datatype to float and used fabs instead of abs in your code and got AC. This is the link to your updated code.
https://www.codechef.com/viewsolution/12272086
whats wrong in this
#include <iostream>
#include<stdlib.h>
using namespace std;
int main() {
double t1,s1,s2,d,t,s;
double a;
std::cin>>t1;
t1--;
do{
std::cin>>s>>s1>>s2>>d>>t;
a=d*3.6*50/t;
a=a+s;
if(abs(a-s1)<abs(a-s2))
std::cout<<"SEBI"<<endl;
if(abs(a-s1)>abs(a-s2))
std::cout<<"FATHER"<<endl;
if(abs(a-s1)==abs(a-s2))
std::cout<<"DRAW"<<endl;
}while(t1--);
// your code goes here
return 0;
}
#include
#include <bits/stdc++.h>
using namespace std;
int main() {
double tc,s,sg,fg,d,t;
double sp=0.00,d1=0.00,t1=0.00;
cin>>tc;
while(tc–)
{
cin>>s>>sg>>fg>>d>>t;
d1=(double)(d50/1000); //distance in km
t1=(double)(t/60); //time in min
sp=(double)(d160/t1); //actual speed of other car
sp=(double)(sp+s);
if((abs)(sg-sp)==(abs)(fg-sp))
cout<<"DRAW"<<endl;
else if((abs)(sg-sp)<(abs)(fg-sp))
cout<<"SEBI"<<endl;
else
cout<<"FATHER"<<endl;
}
return 0;
}
please tell me what is wrong in this code?..Its giving me wrong answer
//here is simple C++ code
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t;
cin>>t;
while(t–)
{
int s,sg,fg,d,T;
cin>>s>>sg>>fg>>d>>T;
if(sg==fg)
cout<<“DRAW”<<endl;
else
{
float dis=50d;
float v=(dis6060)/(1000T);
v+=s;
if(fabs(v-sg)<fabs(v-fg))
cout<<“SEBI”<<endl;
else if(fabs(v-sg)>fabs(v-fg))
cout<<“FATHER”<<endl;
else
cout<<“DRAW”<<endl;
}
}
return 0;
}
Can someone please tell me what is wrong. Tried many test cases and works for all but still getting wrong answer
https://www.codechef.com/viewsolution/12641292
@rchandu
I had a look at your code and found this
"System.out.println(speed);"
The output CLEARLY says to print only “SEBI” or “FATHER” or “DRAW”
If you print out ANYTHING ELSE, like speed etc. Then the online judge (which is NOT a human) will flag your answer as wrong result. Follow output format closely, as even an extra blank space or full stop or comma will get you a wrong answer
Hope it helps
Can someone help me here? What is missing in my code? I am getting a WA.
https://www.codechef.com/viewsolution/15176177
using std::abs might help see my ans below for detail.
https://discuss.codechef.com/questions/87910/sebihwy-editorial/87954
try using the expression given in the editorial.for details my ans below.
try using fabs. and simplifying the expression
but, it’s the same thing, the expression given in the editorial is just more simplified than what I’ve written, it should give AC in both the cases. Still can’t figure out where I went wrong…
please read the ans below when you divide first you lose precision as there are only say 19 digits after the decimal. Moreover expression d/1000/tx50x3600 yields wrong ans but dx3600x50/t/1000 yields right answer. You should check the links in my answer. I tried almost 40 diff. solutions to check this out.