In past codeforces contest I was submitting code in C++17 ans it is showing WA while when same code is submitted in C++14 it got accepted can anyone tell me why this is happened
C++17 Wa code
C++14 Accepted code
2 Likes
I see you are using ceil. Can you try once without it and let us know the results?
I think its not because of the c++ version but its about floating point errors that arises during divisions and sometimes causes wrong answer.
These errors arises generally when you are doing some calculations like
(a/b) > k or something like that to get rid of such errors avoid division.
for example if you want to check if
(a/b) <= k
Then change this as (a <= k*b)
Try changing all your division operations into inverse multiplication and try submitting it again… because i used C++17 with almost same approach what you have done and got AC. so most probably that’s the reason for WA.
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Yes, you’re right, I faced the same problem and then changed float to double
Here is my integer solution of the problem.
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lemme check 
Your Code That got AC see what i edited
#include<bits/stdc++.h>
#include<assert.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;
#define Fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define fo(i,s,n) for(int i=s;i<n;i++)
#define mod 1000000007
void fun();
ll digit(ll num,ll d);
int main()
{
ll t;
cin>>t;
while(t--)
{
fun();
}
return 0;
}
void fun()
{
ll n,k;
cin>>n>>k;
ll arr[n];
fo(i,0,n)
{
cin>>arr[i];
}
ll price=arr[0];
ll ans=0;
fo(i,1,n)
{
if(arr[i]*100 > price*k)
{
ll a=ceil(((double)arr[i]*100)/k);
ans+=abs(a-price);
price+=abs(a-price);
//cout<<a<<" "<<ans<<" "<<price<<endl;
}
price+=arr[i];
}
cout<<ans<<endl;
return;
}
okay thank you but why it got accepted in c++14 same code according to me it should also show WA
- It may be because handling of floating numbers in
c++14differs fromc++17. - I really don’t have any deep knowledge on this but to know you can refer this documentation :