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:

The Doge 2021

PAST CHALLENGES

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

Calculate cheapest way of buying gas in order to drive along a highway.

There are N+1 towns numbered from 0 to N lying along a highway. The distances between towns, and gas prices in each town, are given. A truck has to deliver cargo from town 0 to town N. What is the cheapest way to buy enough gas for this trip?

Two non-empty arrays D (distances) and P (prices), each consisting of N positive integers, and a positive integer T (tank capacity) are given. Consider any sequence R (refill strategy) consisting of N non-negative integers (amount of fuel bought in each town).

Sequence L (amount of fuel when leaving town), consisting of N integers, is defined as follows:

L[K] = (R[0] + ... + R[K]) − (D[0] + ... + D[K−1]) for 0 ≤ K ≤ N−1

Sequence A (amount of fuel when arriving at town), consisting of N integers, is defined as follows:

A[K] = L[K−1] − D[K−1] for 1 ≤ K ≤ N

The following conditions (meaning that the truck must not run out of fuel and cannot fill up with more fuel than its tank capacity) must hold:

- 0 ≤ L[K] ≤ T for 0 ≤ K ≤ N−1

- 0 ≤ A[K] ≤ T for 1 ≤ K ≤ N

Number C (total cost of refill strategy) is defined as:

C = R[0] * P[0] + ... + R[N−1] * P[N−1]

For example, consider T = 15 and the following arrays D and P, consisting of three elements each:

Sequence [15, 10, 2] is a refill strategy with cost 46. Sequence [10, 5, 12] is not a valid refill strategy, because the truck would run out of fuel between towns 1 and 2. Sequence [10, 15, 2] is a refill strategy with cost 41, and no cheaper refill strategy exists for this choice of arrays D, P and number T.

Write a function:

class Solution { public int solution(int[] D, int[] P, int T); }

that, given two non-empty arrays D and P consisting of N positive integers each and a positive integer T, returns the cost of the cheapest refill strategy for D, P and T.

The function should return −1 if no valid refill strategy exists.

The function should return −2 if the result exceeds 1,000,000,000.

For example, given T = 15 and arrays D and P consisting of three elements each such that:

the function should return 41, as explained above.

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

- T is an integer within the range [1..1,000,000];
- N is an integer within the range [1..100,000];
- each element of arrays D, P is an integer within the range [1..1,000,000].

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