Обсуждение @ 1118. Нетривиальные числа @ Timus Online Judge

Grab a bit incorrect task [4] // Задача 1118. Нетривиальные числа 10 фев 2006 12:06

In the task of problem #1118 the triviality(1) was not defined.
test #4 has 1 as i.
after putting triviality(1) be equal to 0, i've gotten AC.
So, in my opinion, this moment should be fixed in the task.

P.S.
sorry for my bad English

Ayhan Aliyev [BOTL] Re: a bit incorrect task [3] // Задача 1118. Нетривиальные числа 10 фев 2006 13:12

Yes I agree with you. Problem definition is unclear.

Vladimir Yakovlev (USU) Re: a bit incorrect task [2] // Задача 1118. Нетривиальные числа 10 фев 2006 14:12

Citation from problem statement:

Recall that a proper divisor of a natural number is the divisor that is strictly less than the number.

So, 1 has no proper divisors and its sum equals to 0. Hence, triviality of 1 equals to 0.

Grab Re: a bit incorrect task [1] // Задача 1118. Нетривиальные числа 10 фев 2006 19:59

Vladimir Yakovlev (USU) писал(a) 10 февраля 2006 14:12

Citation from problem statement:

Recall that a proper divisor of a natural number is the divisor that is strictly less than the number.

So, 1 has no proper divisors and its sum equals to 0. Hence, triviality of 1 equals to 0.

Sorry, but I do not agree with you.
0 is less then 1, but it is not its divisor.
So, we have a sutuation: there's NO divisor (that's why the sum is not 0, but it doesn't exist), strictly the function doesn't have any value at 1 (т.е. функция не определена в точке 1), but nil is a number and the condition Triv(1)=0 means it has it!
that what wanted to say.

P.S.
sorry for using Russian, but I really do not know how to explain my think in English

Edited by author 10.02.2006 20:00

Edited by author 10.02.2006 20:20

Vladimir Yakovlev (USU) Re: a bit incorrect task // Задача 1118. Нетривиальные числа 11 фев 2006 03:23

In maths the sum of empty set of numbers is traditionally considered to be equal to zero.

Обсуждение задачи 1118. Нетривиальные числа