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Fibonacci With Case

Terminal - Fibonacci With Case
fib(){ case $1 in 0)echo 0;;1)echo 1;;[0-9]*)echo $[$(fib $[$1-2])+$(fib $[$1-1])];;*)exit 1;;esac;}
2010-06-28 19:41:44
User: kzh
Fibonacci With Case

Returns the '$1'th Fibonacci number.


There is 1 alternative - vote for the best!

Terminal - Alternatives

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What others think

recursively finding fibonacci sequences is a really good way to freeze any system up

use a for loop for a more efficient calculation

Comment by amanharan 251 weeks and 5 days ago

If one were worried about efficiency, then one should not use a shell script.

This was quick to write. Thanks for the input.

Comment by kzh 251 weeks and 5 days ago
fib(){ k=0; l=1; for i in `seq 1 $1`; do t=$l; l=$(($l + $k)); k=$t; done; echo $k;}

also quick to write, but much faster

Comment by fpunktk 251 weeks and 5 days ago

fpunktk: 93th and some others afterwards are negative, why is that?

Comment by alperyilmaz 251 weeks and 5 days ago

I had never really used bash case statements before and was trying them out. If I really wanted to use large numbers, I would have done:

python -c 'def fib(n):

if n not in fibs:fibs[n]=fib(n-1)+fib(n-2)

return fibs[n]

import sys;fibs={0:0,1:1};print fib(int(sys.argv[1]))' 7


Comment by kzh 251 weeks and 5 days ago

Your point of view

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