Help, please. p1387 - Vasya's Father. What is answer for n = 8?
Mine is 117, but I have WA on test #8. I can't find a mistake in my code :(
Thanks! Re: Help, please. p1387 - Vasya's Father. Послано md 4 ноя 2005 13:25 I have WA#8 too. Where was your mistake?
Some values I calculated:
"1",
"1",
"2",
"4",
"9",
"20",
"49",
"117",
"297",
"746",
"1947",
"5021",
"13378",
"35237",
"95123",
"254825",
"694987",
"1882707",
"5184391",
"14177587",
"39289183",
"108337723",
"301997384",
"837774846",
"2347293253",
"6546903307",
"18417850843",
"51617715836",
"145722478875",
... Your sequence not right (+) right is
1, 1, 2, 4, 9, 20, 48, 115,..
My mistake was for n = 7:
Your think that there
f(7) = f(6) + f(5)*f(1) + f(4)*f(2) + f(3)*f(3) + f(4)*f(1)*f(1) + ...
But correct is:
f(7) = f(6) + f(5)*f(1) + f(4)*f(2) + f(3)*(f(3)+1)/2! + f(4)*f(1)*(f(1)+1)/2! + ...
so we will take not f(3)*f(3) = 2*2 = 4, but f(3)*(f(3)+1)/2! = 2*(2+1)/2! = 3, and f(7) = 48.
Edited by author 04.11.2005 18:12 Thank you (+) Thank you very much for your hint! It turned out to be very-very useful for me. Without it I would have spent many hours debugging... Re: Your sequence not right (+) Послано labike 11 авг 2013 16:38 can you let me see you code ? i just can not ac it ,,,thanks,,, |
