Utopian Tree | HackerRank Solution

Hello coders, today we are going to solve Utopian Tree HackerRank Solution which is a Part of HackerRank Algorithm Series.

Task

The Utopian Tree goes through 2 cycles of growth every year. Each spring, it doubles in height. Each summer, its height increases by 1 meter.

A Utopian Tree sapling with a height of 1 meter is planted at the onset of spring. How tall will the tree be after n growth cycles?

For example, if the number of growth cycles is n = 5, the calculations are as follows:

Period  Height
0          1
1          2
2          3
3          6
4          7
5          14

Function Description

Complete the utopianTree function in the editor below.

utopianTree has the following parameter(s):

• int n: the number of growth cycles to simulate

Returns

• int: the height of the tree after the given number of cycles

Input Format

The first line contains an integer, t, the number of test cases.
t subsequent lines each contain an integer, n, the number of cycles for that test case.

Constraints

• 1 <= t <= 10
• 0 <= n <= 60

Sample Input

3
0
1
4

Sample Output

1
2
7

Explanation

There are 3 test cases.

In the first case (n = 0), the initial height (H = 1) of the tree remains unchanged.

In the second case (n = 1), the tree doubles in height and is 2 meters tall after the spring cycle.

In the third case (n = 4), the tree doubles its height in spring (n = 1, H = 2), then grows a meter in summer (n = 2, H = 3), then doubles after the next spring (n = 3, H = 6), and grows another meter after summer (n = 4, H = 7). Thus, at the end of 4 cycles, its height is 7 meters.

Solution – Utopian Tree

C++

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int T;
    cin >> T;
    for(int t = 0; t<T; t++){
        int N;
        cin >> N;
        int ht = 1;
        for(int i=0;i<N;i++){
            if(i%2==0) ht*=2;
            else ht++;
        }
        cout << ht << endl;
    }
    return 0;
}

Python

import sys


if __name__ == '__main__':
    T = int(sys.stdin.readline())
    
    for _ in range(T):
        N = int(sys.stdin.readline())
        height = 1
        
        for i in range(N):
            if i % 2 == 0:
                height *= 2
            else:
                height += 1
        print(height)

Java

import java.util.Scanner;
import java.util.Vector;

public class Solution {
    public static void main(String[] args) {
        Scanner stdin = new Scanner(System.in);
        int numCases = stdin.nextInt();
        Vector<Long> cache = new Vector<>();
        cache.add(1L);
        for (int i = 0; i < numCases; i++) {
            int numCycles = stdin.nextInt();
            while(cache.size() <= numCycles) {
                if (cache.size() % 2 == 0) {
                    cache.add(cache.lastElement() + 1);                
                } else {
                    cache.add(cache.lastElement() * 2);
                }
            }
            System.out.println(cache.get(numCycles));
        }
    }
}

Disclaimer: The above Problem (Utopian Tree) is generated by Hacker Rank but the Solution is provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.