AE2A - Dice

Jack claims that he has telekinetic powers. He has made a bet with Mike that he would throw a die n times and would get exactly k pips in total. Jack's die has 6 faces with numbers from 1 to 6 written on them and is perfectly symmetric. Mike does not believe in Jack's telekinetic powers (in general, being a tenacious rationalist, he does not believe in telekinesis), but he is concerned that Jack could win the bet simply by luck. Therefore, he would like to know what is the chance (in percent) of such an unlucky event, and asked you to write a program that would help him solve this problem.


The first line of the standard input contains a single integer t (1 ≤ t ≤ 20) denoting the number of test cases. Each of the following t lines contains a description of one test case in the form of two integers ni and ki (1 ≤ ni, ki ≤ 106) separated by a single space.


To the standard output t lines should be written, containing the answers to respective test cases. The answer to one test case is the probability (in percent) that Jack wins the bet, rounded down to the nearest integer.


For the input data:

1 6

the correct result is:


Task author: Jakub Onufry Wojtaszczyk.

hide comments
yashmittal: 2016-03-02 09:44:55

can anyone explain how (3,6) will give 0 probablity percent of getting 6 when dice is rolled 3 times

Last edit: 2016-03-03 08:57:58
sarvesh_19: 2016-02-19 22:55:31

bottom up recursion giving tle iterative top down accepted. please help :(

r_ash: 2016-01-20 08:33:00

the total number of favorable cases is larger than the range of unsigned long long int...what can I do now?

Last edit: 2016-01-20 08:33:15
DHEERAJ KUMAR: 2016-01-16 22:17:10

extremely fucking problem. same code after 30 submissions showed AC. Dont race with time while setting problems.

Piyush Kumar: 2015-12-11 08:51:26

@shyam , There are no trick test cases as such. I wrote a straightforward dp solution and it passed.

Amit Ajaat: 2015-06-30 16:00:20

YOU "Race with time" , atleast, explain the problems clearly, hiding something is not going to make you best coder or best problem setter.......what this pips represent, what "exactly k pips in total" means, you are the one who is
expected to explain. You are the one setting question not those who are explaining in comments.....irritating it good next time!!!!

shyam: 2015-06-19 07:54:56

wrong answer ...any trick test cases??

Brian Bi: 2009-09-30 08:53:35

A pip is simply one of those marks on the face of a die. So "exactly k pips in total" should be interpreted as "a sum of k".

Added by:Race with time
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Algorithmic Engagements 2009