FIBEASY - Unofficial Editorial

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41

Can anyone explain what is wrong with my code. I tried to find the position of ith power of 2 which will be the element of Fibonacci number left after process end still I am getting wrong answer verdict this is link to my solution CodeChef: Practical coding for everyone

42

It fails on the testcase

1
64

(the answer should be 2, but on my machine, yours gives 3).

43

can you explain me how to solve this @ssjgz

44

Horrible Rounding off errors at work!
See how this doesnā€™t work, even though I built the log function myself: CodeChef: Practical coding for everyone
And how this clever workaround works: CodeChef: Practical coding for everyone

Very disappointed that built in log doesnā€™t work even in case of python

45

Use log2l() function instead of log2().
I was stuck here too xD.

46

Use log2l instead :slight_smile:

47

Bruh wtf :rofl::rofl::rofl::rofl: (20char)

1 Like
48

Can anyone point out my mistake. Itā€™s working properly for smaller constraints but showing wrong ans for larger constraints.
https://www.codechef.com/viewsolution/26642928

49

Like many solutions, it fails on the testcase:

1
18014398509481984

presumably due to your use of pow.

50

Thank you, really helped.
When I was using pow() it was showing correct result in the code blocks.
It was creating problem only when I was submitting in the code chef.

1 Like
51

Can anyone tell me whats wrong with my solution getting 20pts.https://www.codechef.com/viewsolution/26645366

52

Its because of using pow() funcn.
Check whether it works for the following case:
1
18014398509481984

53

why the answer will be 2 ?

54 
Initial D: 
 0 1 1 2 3 5 8 3 1 4 5 9 4 3 7 0 7 7 4 1 5 6 1 7 8 5 3 8 1 9 0 9 9 8 7 5 2 7 9 6 5 1 6 7 3 0 3 3 6 9 5 4 9 3 2 5 7 2 9 1 0 1 1 2
New D:
 1 2 5 3 4 9 3 0 7 1 6 7 5 8 9 9 8 5 7 6 1 7 0 3 9 4 3 5 2 1 1 2
New D:
 2 3 9 0 1 7 8 9 5 6 7 3 4 5 1 2
New D:
 3 0 7 9 6 3 5 2
New D:
 0 9 3 2
New D:
 9 2
New D:
 2
solutionBruteForce: 2
55

Sir at n=64 where n is the number of index starting from 1
we get Fibonacci number at n=64 as 10610209857723 so its mod by 10 will give 3 ?

please help!

56

Iā€™m just following the instructions in the Problem Statement:

Initial D: 
FN_0%10 = 0 , FN_1%10 = 1 , FN_2%10 = 1 , FN_3%10 = 2 , FN_4%10 = 3 , FN_5%10 = 5 , FN_6%10 = 8 , FN_7%10 = 3 , FN_8%10 = 1 , FN_9%10 = 4 , FN_10%10 = 5 , FN_11%10 = 9 , FN_12%10 = 4 , FN_13%10 = 3 , FN_14%10 = 7 , FN_15%10 = 0 , FN_16%10 = 7 , FN_17%10 = 7 , FN_18%10 = 4 , FN_19%10 = 1 , FN_20%10 = 5 , FN_21%10 = 6 , FN_22%10 = 1 , FN_23%10 = 7 , FN_24%10 = 8 , FN_25%10 = 5 , FN_26%10 = 3 , FN_27%10 = 8 , FN_28%10 = 1 , FN_29%10 = 9 , FN_30%10 = 0 , FN_31%10 = 9 , FN_32%10 = 9 , FN_33%10 = 8 , FN_34%10 = 7 , FN_35%10 = 5 , FN_36%10 = 2 , FN_37%10 = 7 , FN_38%10 = 9 , FN_39%10 = 6 , FN_40%10 = 5 , FN_41%10 = 1 , FN_42%10 = 6 , FN_43%10 = 7 , FN_44%10 = 3 , FN_45%10 = 0 , FN_46%10 = 3 , FN_47%10 = 3 , FN_48%10 = 6 , FN_49%10 = 9 , FN_50%10 = 5 , FN_51%10 = 4 , FN_52%10 = 9 , FN_53%10 = 3 , FN_54%10 = 2 , FN_55%10 = 5 , FN_56%10 = 7 , FN_57%10 = 2 , FN_58%10 = 9 , FN_59%10 = 1 , FN_60%10 = 0 , FN_61%10 = 1 , FN_62%10 = 1 , FN_63%10 = 2 
New D:
FN_1%10 = 1 , FN_3%10 = 2 , FN_5%10 = 5 , FN_7%10 = 3 , FN_9%10 = 4 , FN_11%10 = 9 , FN_13%10 = 3 , FN_15%10 = 0 , FN_17%10 = 7 , FN_19%10 = 1 , FN_21%10 = 6 , FN_23%10 = 7 , FN_25%10 = 5 , FN_27%10 = 8 , FN_29%10 = 9 , FN_31%10 = 9 , FN_33%10 = 8 , FN_35%10 = 5 , FN_37%10 = 7 , FN_39%10 = 6 , FN_41%10 = 1 , FN_43%10 = 7 , FN_45%10 = 0 , FN_47%10 = 3 , FN_49%10 = 9 , FN_51%10 = 4 , FN_53%10 = 3 , FN_55%10 = 5 , FN_57%10 = 2 , FN_59%10 = 1 , FN_61%10 = 1 , FN_63%10 = 2 
New D:
FN_3%10 = 2 , FN_7%10 = 3 , FN_11%10 = 9 , FN_15%10 = 0 , FN_19%10 = 1 , FN_23%10 = 7 , FN_27%10 = 8 , FN_31%10 = 9 , FN_35%10 = 5 , FN_39%10 = 6 , FN_43%10 = 7 , FN_47%10 = 3 , FN_51%10 = 4 , FN_55%10 = 5 , FN_59%10 = 1 , FN_63%10 = 2 
New D:
FN_7%10 = 3 , FN_15%10 = 0 , FN_23%10 = 7 , FN_31%10 = 9 , FN_39%10 = 6 , FN_47%10 = 3 , FN_55%10 = 5 , FN_63%10 = 2 
New D:
FN_15%10 = 0 , FN_31%10 = 9 , FN_47%10 = 3 , FN_63%10 = 2 
New D:
FN_31%10 = 9 , FN_63%10 = 2 
New D:
FN_63%10 = 2 
solutionBruteForce: 2
1 Like
57

what FN means ?

58

Sorry, thatā€™s a typo - should just be F.

1 Like
59

sirā€¦
we have Fibonacci no as
0 1 1 2 3 5 8 13 21 34 55 89ā€¦
if in question letā€™s say we are given n=64
then we know that at 64th position the number is 10610209857723
by eliminating odd position each time we will have n=64 at last.
and 10610209857723%10 will be 3 then why the answer will be 2

60

sir please help

we have Fibonacci no as
0 1 1 2 3 5 8 13 21 34 55 89ā€¦
if in question letā€™s say we are given n=64
then we know that at 64th position the number is 10610209857723
by eliminating odd position each time we will have n=64 at last.
and 10610209857723%10 will be 3 then why the answer will be 2