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:

May the 4th Challenge

PAST CHALLENGES

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

Count the number of islands on consecutive days.

The city of Codicity is located at the seaside. The city area comprises N plots located along a boulevard on one side of the city. Each plot is flat, but different plots have different heights above the sea level. The relative heights of the consecutive plots are given in the form of a non-empty array A of N integers.

The sea level changes constantly and many plots are sometimes under water. Water levels on consecutive days are given in the form of a non-empty array B of M integers.

A *slice* of array A is any pair of integers (P, Q) such that 0 ≤ P ≤ Q < N. An *island* is a slice of consecutive plots that rise above the water’s surface. The plots on either side of each island are under water. More precisely, if the level of the water is K, then an island is a slice (P, Q) in which the level of each plot A[P], A[P + 1], ..., A[Q] is greater than K. Both of the adjacent plots should also be under water; that is:

- P = 0 or A[P − 1] ≤ K
- Q = N − 1 or A[Q + 1] ≤ K

The goal is to calculate the number of islands on consecutive days.

For example, given the following arrays A and B:

We have the following number of islands on consecutive days:

- on the first day there is only 1 island: (0, 4),
- on the second day there are 2 islands: (0, 0) and (2, 4),
- on the third day there are 2 islands: (2, 2) and (4, 4),
- on the fourth day there aren't any islands,
- on the fifth day there are 2 islands: (0, 0) and (2, 4).

Write a function:

class Solution { public int[] solution(int[] A, int[] B); }

that, given a non-empty array A of N integers and a non-empty array B of M integers, returns a sequence consisting of M integers representing the number of islands on consecutive days.

Result array should be returned as an array of integers.

For example, given:

the function should return the array [1, 2, 2, 0, 2], as explained above.

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

- N and M are integers within the range [1..30,000];
- each element of arrays A, B is an integer within the range [0..100,000].

Copyright 2009–2021 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.