Here is my solution in java, javascript, python, C, C++, Csharp HackerRank Chief Hopper Problem Solution

C++

int chiefHopper(vector<int> h) {
    int n = h.size();
    int end = 0;
    int tem = 0;
    for (int i = n - 1; i >= 0; i--) {
        tem = end + h[i];
        if (tem % 2 == 0) end = tem / 2;
        else end = tem / 2 + 1;
    }
    return end;
}

Python 3. The idea is to work backwards assuming that the final energy must be 0 or 1.

def chiefHopper(arr):
    e=0
    for h in arr[::-1]:
        e=(e+h+1)//2
    return e

Here is the solution of Chief Hopper Click Here

I have a one question with Python3. I use formula "e_0 \geq {\sum^{i}_{j=1}2^{i-j}*h_j\over{2^i}}" from e_i = 2^{i}*e_0 - \sum^{i}_{j=1}2^{i-j}*h_j

When I try to submit my code, only one case is failed and I found it 99999+(99999/(2^1000)) == 99999. I want to why it works like this and how to solve this problem.

Here is my python3 code:

def chiefHopper(arr):
    # Write your code here
    min_energy = 0.0
    for i in range(len(arr)):
        min_energy += arr[i]/(2**(i+1))
    return math.ceil(min_energy)