The problem is from a recent competition on Codechef. According to the problem, for a given array of length N, find the maximum average of the numbers of any contiguous sub-array of length between A and B.
Now here is the logic that I have used. I have in a loop iterated over the possible contiguous sub-array length K from A to B. Then for every such K, I have used the sliding window mechanism to find the maximum sum of contiguous elements of the array. Then I check if the already stored answer (the average) is smaller than the current maximum/K and update the answer.
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{
int n,b,a;
cin>>n>>b>>a;
long long arr[n+1];
for(int i=1;i<=n;i++)
{
cin>>arr[i];
}
double ans=0;
for(int k=a;k<=b;k++)
{
long long maxi=0;
for(int i=1;i<=k;i++)
{
maxi=maxi+arr[i];
}
long long l=maxi;
for(int i=k+1;i<=n;i++)
{
l=l+arr[i]-arr[i-k];
maxi=max(maxi,l);
}
double x=(double)(((double)(maxi))/(double)(k));
ans=max(ans,x);
}
cout<<ans<<endl;
}
}
However, after implementing my logic over as shown, I am getting wrong answers even though I do not know how different they are the actual answer since I have not obtained anything wrong in my processes of debugging.
The following is an edit: Are my previous code and the following the same?
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{
int n,b,a;
cin>>n>>b>>a;
long long arr[n+1];
for(int i=1;i<=n;i++)
{
cin>>arr[i];
}
long double ans=0;
for(int k=a;k<=b;k++)
{
long long l=0;
for(int i=1;i<=k;i++)
{
l=l+arr[i];
}
ans=max(ans,(long double)(((long double)(l))/(long double)(k)));
for(int i=k+1;i<=n;i++)
{
l=l+arr[i]-arr[i-k];
ans=max(ans,(long double)(((long double)(l))/(long double)(k)));
}
}
cout<<ans<<endl;
}
}
