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:

Molybdenum 2019

PAST CHALLENGES

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

ambitious

Given a string of letters 'M' and 'L', compute the minimum number of changes needed to obtain a string such that the length of its longest interval of letters 'M' is equal to K.

Programming language:

A long time ago, when the most basic model of an HP3000 computer used to cost $95,000 (over half a million in today's dollars), a very wise man called Gordon Moore made predictions about how computers would become cheaper and more powerful each year. According to Moore, the number of components per integrated circuit would double every two years. Thanks to the creative, determined engineers working in circuit printing technology, we do indeed have smaller, cheaper and more powerful computers today.

Circuit printing, as we call photolithography, is an extremely complex yet rewarding field, and ASML needs the best software engineers in the world to make this magic happen. We work closely with our clients to help them print their circuits in the most effective way. One of our clients requests us to write a method to optimize their circuit efficiency. The circuit is represented as a string consisting of the letters "M" and "L", where M represents Memory units and L represents Logic units. The efficiency of the circuit is measured as the length of the longest interval of letters "M". For example, given input string "LMMMLMMMMLLLM", the longest interval is 4.

Our customer wants to change the circuit in such a way that the longest M-interval will be equal to K. We can change any unit at any position in the circuit, i.e. either we can change any "M" to "L" or any "L" to "M". The objective of this challenge is to calculate the minimum number of changes we have to make in order to achieve the desired longest M-interval length K.

Write a function:

class Solution { public int solution(String S, int K); }

where the first argument, S, represents the circuit as a string of length N that consists of only characters "M" and/or "L" and the second argument, K, is the desired longest M-interval in the string. The return value shall be the minimum number of changes to achieve K as the longest M-interval in the input string.

For example, given S = "MLMMLLM" and K = 3, your function should return 1. We can change the letter at position 4 (counting from 0) to obtain "MLMMMLM", in which the longest interval of letters "M" is exactly three characters long.

For another example, given S = "MLMMMLMMMM" and K = 2, your function should return 2. We can, for example, modify the letters at positions 2 and 7 to get the string "MLLMMLMLMM", which satisfies the desired property.

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

- string S consists only of the characters "
M" and/or "L";- N is an integer within the range [1..100,000];
- K is an integer within the range [0..N].