10916 - Factstone Benchmark

[kp]

Hi!!
I feel this problem is very simple but i keep getting WA. isnt the answer same for 1960-1969,1970-1979,...
please give me some test cases. please help me..

regards,
Pradeep

Yes, answer is the same for XXX0 - XXX9.
Test:

Code: Select all

1960
2160
2101
1999
1982
0

Answer:

Code: Select all

3
254016
5910
12
8

[soyoja]

This is so simple problem, and I use my BigInteger class

( I think it's so fast )

But When my test year exceed 2100 then running speed

was seriously slower. ( it must calculate over 3000! )

Is there any technique for solving this problem?

Plz tell me about hint.

// my pseudo code

while( bits can represent factorial )
{
next_number++;
factorial *= next_number;
}

return next_number;

[wook]

well, biginteger method would not be so fast,
since artimethic using BigInteger is too slow to process such a big number,
thus you cannot use BIGINTEGER method!

Think about logarithms, then problem becomes more simple.

hint) log(100!) = log(1 * 2 * 3 * ... * 100) = log1 + log2 + ... + log100

[Martin Macko]

This is so simple problem, and I use my BigInteger class

( I think it's so fast )

But When my test year exceed 2100 then running speed

was seriously slower. ( it must calculate over 3000! )

Is there any technique for solving this problem?

Plz tell me about hint.

// my pseudo code

while( bits can represent factorial )
{
next_number++;
factorial *= next_number;
}

return next_number;

Think about this sentence in the problem statement:

Given a year 1960 ≤ y ≤ 2160

[Ankur Jaiswal]

isnt the answer going to be
the 21 values
for the set of years??
if yes then why am i getting WA?otherwise where am i wrong?
is there any boundary condition?

[mamun]

isnt the answer going to be
...
for the set of years??

Do you understand that set of years is [1960,2160]?

[Ankur Jaiswal]

so that is what i am saying..
3 for the set of years 1960-1969
5 for 1970-1979
and so on.
isn't that rite?

[mamun]

That is right. The I/O specification is too straightforward to do a mistake. Anyway you can try this

Code: Select all

1999
2000
2001
1960
1961
2160
2159
2160

[Ankur Jaiswal]

12
20
20
3
3
254016
134480
254016

[DD]

12
20
20
3
3
254016
134480
254016

Your output is identical mine. I think your functionality should be right, but you may need to check that your program can terminate correctly or not.

[uDebug]

Replying to follow this thread.