HackerEarth Help Fredo problem solution

In this HackerEarth Help, Fredo problem solution Fredo is assigned a task today. He is given an array A containing N integers. His task is to update all elements of array to some minimum value x, that is, A[i] = x; 1 <= i <= N  such that product of all elements of this new array is strictly greater than the product of all elements of the initial array. Note that x should be as minimum as possible such that it meets the given condition. Help him find the value of x.

HackerEarth Help Fredo with problem solution.

#include<bits/stdc++.h>
#define ll long long
#define ld long double
using namespace std;
ll a[100005];
int n;
int main()
{
    cin>>n;
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        assert(a[i]>=1 && a[i]<=1e10);
    }
    sort(a,a+n);
    ld val=0;
        for (int i=0;i<n;i++)
                val+= (ld)(log((ld)(a[i])));
        ll left=a[0],right=a[n-1]+1,ans;
        while(left<=right)
        {
                ll mid=(left+right)/2;
                ld temp= (ld)n * (ld)(log((ld)(mid)));
                if(val < temp)
                {
            ans=mid;
            right=mid-1;
        }
                else
            left=mid+1;
        }   
    cout<<ans<<"\n";
    return 0;
}