Discussion @ 1692. Flags for Provinces @ Timus Online Judge

Phan Hoài Nam - Đại học Ngoại ngữ Tin Học TP.HCM example is wrong ??? n = 4 => k = 4 [7] // Problem 1692. Flags for Provinces 14 Mar 2009 14:57

n = 4
answer :
4
2 1 2
2 1 4
2 2 3
2 3 4

Dimitar Jelev Re: example is wrong ??? n = 4 => k = 4 [1] // Problem 1692. Flags for Provinces 14 Mar 2009 15:01

no. 1 2 & 3 4 does not have a common color

Phan Hoài Nam - Đại học Ngoại ngữ Tin Học TP.HCM Re: example is wrong ??? n = 4 => k = 4 // Problem 1692. Flags for Provinces 14 Mar 2009 15:12

Thanks Dimitar Jelev

program_lover Re: example is wrong ??? n = 4 => k = 4 [4] // Problem 1692. Flags for Provinces 14 Mar 2009 15:31

my opinion
answer:
4
3 1 2 3
3 1 2 4
3 1 3 4
3 2 3 4

Smilodon_am Re: example is wrong ??? n = 4 => k = 4 [1] // Problem 1692. Flags for Provinces 14 Mar 2009 15:45

The right answer for n=4 is k=3
3
3 1 2 3
3 1 2 4
2 3 4
Previous answer
<<
4
3 1 2 3
3 1 2 4
3 1 3 4
3 2 3 4
>>
is wrong because the 1st colour is used 3 times.

Because my proposed answer is k=3, so the answer in problemset is right. Authors did not use the 4th colour because they can make 3 flags with 3 colours. It is only their choice.

Adler3D Re: example is wrong ??? n = 4 => k = 4 // Problem 1692. Flags for Provinces 14 Mar 2009 15:59

Smilodon_am, MegaThanks You!

ЗЫ: коварное условие :)
PS: insidious conditions :)

beriba Re: example is wrong ??? n = 4 => k = 4 [1] // Problem 1692. Flags for Provinces 14 Mar 2009 15:47

"he doesn't want any colour to occur in three or more flags"
read whole problem ;)

program_lover Re: example is wrong ??? n = 4 => k = 4 // Problem 1692. Flags for Provinces 14 Mar 2009 16:13

Thanks beriba

Discussion of Problem 1692. Flags for Provinces