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quickly finding the number of digits required for nth fibonacci number in C++
By pistone, 15 years ago, In English

for me it wa quite a problem , since i strictly used C++ to solve it.

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15 years ago, hide # |
 
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my fault , sorry 

actually the problem is :  finding the minimum c++ variable type(byte,short,int,long etc)  in which nth fibonacci number can be accomodated .
 
if it cant be accomodated in c++ standard var types then print  "BigInteger" .

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  • 15 years ago, hide # ^ |
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    It is all the same, just use log2 instead of log10.

    However, since Fibonacci sequence grows fast, you can write program for direct computation.

    UPD: Or you mean "help me to write the program for Fibonacci sequence computation?"
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15 years ago, hide # |
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You can just generate locally all those Fib numbers and remember n values: ai is such that Fai is a max number that fits in ith type.
After that just some if's.
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