ENG  RUSTimus Online Judge
Online Judge
Problems
Authors
Online contests
About Online Judge
Frequently asked questions
Site news
Webboard
Links
Problem set
Submit solution
Judge status
Guide
Register
Update your info
Authors ranklist
Current contest
Scheduled contests
Past contests
Rules
back to board

Discussion of Problem 2090. Crossroads of Destiny

Question about problem
Posted by Felix_Mate 29 Apr 2018 18:19
1)What meaning of "equiprobable initial state"? P{state is GreenRed}=t1/(t1+t2+t3+t4), P{state is YellowRed}=t2/(t1+t2+t3+t4) ?

2)Can Sergey cross the street of Marks and then Engels, or first cross Engels and then Marks?
Re: Question about problem
Posted by Shen Yang 30 Apr 2018 10:48
1)equiprobable initial state means it is equal probablity initial time is [0,t1+t2+t3+t4]

2) sergey has two choice:  first cross crosswalk (which needn't wait just go directly) then cross

engels street (maybe wait for green traffic light)

second choice is first cross marks street(wait for green) then cross  engels street(wait for green) (maybe he can first cross engels streect then marks street just choose optimal time.i.e. which green traffic arrive first,just first cross it..)

distance of both choice are equal...

Edited by author 30.04.2018 10:58

Edited by author 30.04.2018 10:59