Your browser (Unknown 0) is no longer supported. Some parts of the website may not work correctly. Please update your browser.

UPCOMING CHALLENGES:

CURRENT CHALLENGES:

Pi Code Challenge

PAST CHALLENGES

Year of the Rabbit

Carol of the Code

Game of Codes

National Coding Week 2022

Jurassic Code

Fury Road

Bug Wars: The Last Hope

Muad'Dib's

Year of the Tiger

Pair a Coder

Code Alone

Gamer's

Spooktober

National Coding Week

The Coder of Rivia

Fast & Curious

The Fellowship of the Code

May the 4th

The Great Code Off 2021

The Doge 2021

The Matrix 2021

The OLX Group challenge

Silver 2020

Palladium 2020

Rhodium 2019

Ruthenium 2019

Technetium 2019

Molybdenum 2019

Niobium 2019

Zirconium 2019

Yttrium 2019

Strontium 2019

Rubidium 2018

Arsenicum 2018

Krypton 2018

Bromum 2018

Future Mobility

Grand Challenge

Digital Gold

Selenium 2018

Germanium 2018

Gallium 2018

Zinc 2018

Cuprum 2018

Cutting Complexity

Nickel 2018

Cobaltum 2018

Ferrum 2018

Manganum 2017

Chromium 2017

Vanadium 2016

Titanium 2016

Scandium 2016

Calcium 2015

Kalium 2015

Argon 2015

Chlorum 2014

Sulphur 2014

Phosphorus 2014

Silicium 2014

Aluminium 2014

Magnesium 2014

Natrium 2014

Neon 2014

Fluorum 2014

Oxygenium 2014

Nitrogenium 2013

Carbo 2013

Boron 2013

Beryllium 2013

Lithium 2013

Helium 2013

Hydrogenium 2013

Omega 2013

Psi 2012

Chi 2012

Phi 2012

Upsilon 2012

Tau 2012

Sigma 2012

Rho 2012

Pi 2012

Omicron 2012

Xi 2012

Nu 2011

Mu 2011

Lambda 2011

Kappa 2011

Iota 2011

Theta 2011

Eta 2011

Zeta 2011

Epsilon 2011

Delta 2011

Gamma 2011

Beta 2010

Alpha 2010

Find the maximum number of towers with same color order that can be obtained from an initial group of tricolored towers if at most one swap of adjacent colors can be performed in every tower.

There are N towers, each made of three single-colored blocks placed one on top of another. The colors of the towers' blocks are described in an array T made of N three-letter strings. String T[K] (for K within the range 0..N−1) describes the colors of the blocks from the bottom to the top of the K-th tower. Colors are represented by lowercase letters.

For each of the towers, we may − at most once − choose two adjacent blocks and swap them. For example, given T[K] = "abc", we may obtain "bac" by swapping the bottom two blocks or "acb" by swapping the top two blocks, or stick with "abc" by not making a swap at all. Our goal is to achieve the same order of colors (from the bottom to the top) in as many towers as possible.

What is the maximum number of towers with the same color order that we can obtain?

Write a function:

class Solution { public int solution(String[] T); }

that, given an array T consisting of N strings representing the towers' colors, returns the maximum number of towers that we can obtain with the same order of block colors.

**Examples:**

1. Given T = ["aab", "cab", "baa", "baa"], the function should return 3. We may create towers ["aba", "cab", "aba", "aba"] by swapping the top two blocks in tower number 0, the bottom two blocks in towers with numbers 2 and 3. This way, towers numbers 0, 2 and 3 will have the same order of colors.

2. Given T = ["zzz", "zbz", "zbz", "dgf"], the function should return 2. It is not necessary to perform any swaps to obtain the result.

3. Given T = ["abc", "cba", "cab", "bac", "bca"], the function should return 3.

Write an ** efficient** algorithm for the following assumptions:

- N is an integer within the range [1..50,000];
- each string in array T consists only of lowercase letters (
a−z);- each string in array T is of length 3.

Copyright 2009–2023 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.