Cut the sticks – HackerRank Solution

In this post, we will solve Cut the sticks HackerRank Solution. This problem (Cut the sticks) is a part of HackerRank Algorithms series.

Task

You are given a number of sticks of varying lengths. You will iteratively cut the sticks into smaller sticks, discarding the shortest pieces until there are none left. At each iteration you will determine the length of the shortest stick remaining, cut that length from each of the longer sticks and then discard all the pieces of that shortest length. When all the remaining sticks are the same length, they cannot be shortened so discard them.

Given the lengths of n sticks, print the number of sticks that are left before each iteration until there are none left.

Example
arr = [1, 2, 3]

The shortest stick length is 1, so cut that length from the longer two and discard the pieces of length 1. Now the lengths are arr = [1, 2]. Again, the shortest stick is of length 1, so cut that amount from the longer stick and discard those pieces. There is only one stick left, arr = [1], so discard that stick. The number of sticks at each iteration are answer = [3, 2, 1].

Function Description

Complete the cutTheSticks function in the editor below. It should return an array of integers representing the number of sticks before each cut operation is performed.

cutTheSticks has the following parameter(s):

• int arr[n]: the lengths of each stick

Returns

• int[]: the number of sticks after each iteration

Input Format

The first line contains a single integer n, the size of arr.
The next line contains n space-separated integers, each an arr[i], where each value represents the length of the i^th stick.

Constraints

• 1 <= n <= 1000
• 1 <= arr[i] <= 1000

Sample Input 0

STDIN           Function
-----           --------
6               arr[] size n = 6
5 4 4 2 2 8     arr = [5, 4, 4, 2, 2, 8]

Sample Output 0

6
4
2
1

Explanation 0

sticks-length        length-of-cut   sticks-cut
5 4 4 2 2 8             2               6
3 2 2 _ _ 6             2               4
1 _ _ _ _ 4             1               2
_ _ _ _ _ 3             3               1
_ _ _ _ _ _           DONE            DONE

Sample Input 1

8
1 2 3 4 3 3 2 1

Sample Output 1

8
6
4
1

Explanation 1

sticks-length         length-of-cut   sticks-cut
1 2 3 4 3 3 2 1         1               8
_ 1 2 3 2 2 1 _         1               6
_ _ 1 2 1 1 _ _         1               4
_ _ _ 1 _ _ _ _         1               1
_ _ _ _ _ _ _ _       DONE            DONE

Solution – Cut the sticks – HackerRank Solution

C++

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

int main(){
    int n;
    cin >> n;
    vector<int> arr(n);
    // Corner case
    if(n == 1) {
        cout<<"1";
        return 0;
    }
    for(int arr_i = 0;arr_i < n;arr_i++){
        cin >> arr[arr_i];
    }
    sort(arr.begin(), arr.end());
    int count = 1;
    cout<<n<<"\n";
    int tmp = n;
    for(int arr_i = 1;arr_i < n;arr_i++){
        if(arr[arr_i] != arr[arr_i-1]) {
            tmp -= count;
            cout<<tmp<<"\n";
            count = 1;
        } else {
            count++;
        }
    }
    return 0;
}

Python

#!/bin/python3

import sys

def cutTheSticks(arr):
    out = []
    while arr:
        out.append(len(arr))
        arr_min = min(arr)
        arr = list(map(lambda x: x - arr_min, arr))
        arr = list(filter(lambda x: x > 0, arr))
        
        
    return out
    

if __name__ == "__main__":
    n = int(input().strip())
    arr = list(map(int, input().strip().split(' ')))
    result = cutTheSticks(arr)
    print ("\n".join(map(str, result)))

Java

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Solution {
    static BufferedReader in = new BufferedReader(new InputStreamReader(
            System.in));
    static StringBuilder out = new StringBuilder();

    public static void main(String[] args) throws IOException {
        int[] stickAmts = new int[1001];
        int numSticks = Integer.parseInt(in.readLine());
        String line = in.readLine();
        String[] data = line.split("\\s+");
        for(int i = 0; i < numSticks; i ++)
        {
            stickAmts[Integer.parseInt(data[i])]++;
        }
        for(int i = 1; i <= 1000; i ++)
        {
            if(stickAmts[i] != 0)
            {
                System.out.println(numSticks);
                numSticks -= stickAmts[i];
            }
        }
    }
}

Note: This problem (Cut the sticks) is generated by HackerRank but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.