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how to calculate amount of zeroes? - Agamemnus - 01-16-2004
I was wondering whether anyone know a quick way to figure out if a number (say n&) is 1, 10, 100, 1000, 10000, 100000, or 1000000, without using loops or long ifs. And without resorting to string methods?
Sort of like figuring out if a number is 50 or 10:
a% = 50
PRINT a% MOD 2
any ideas?
how to calculate amount of zeroes? - whitetiger0990 - 01-16-2004
is it trailing zeros? i.e. 103000 would return 3?
how to calculate amount of zeroes? - oracle - 01-16-2004
LOG (base 10)
numzeroes% = log(10) 100000&
I think...
how to calculate amount of zeroes? - SCM - 01-16-2004
You can use LOG(n&) / Ln10, where Ln10 = LOG(10).
If n& is a power of ten it will give you the number of zeros.
how to calculate amount of zeroes? - whitetiger0990 - 01-16-2004
while were talking about LOG... what exactly is it? o.O
how to calculate amount of zeroes? - SCM - 01-16-2004
A log is the power of a base that equals the number. Since 1000 = 10^3, the log base 10 of 1000 is 3.
It also works with decimals. 10 = 2^3.3219...., so the log base 2 of 10 is 3.3219....
In QB LOG finds the log of a special base, e = 2.71828... In math classes this log will be called ln (the natural log).
To solve Aga's problem, I wanted to find the power of 10, which tells me the number of zeros. The power of 10 is the log base 10. To find that I divided the LOG of the number by the LOG of 10.
Log_Base_10 = LOG(Number) / LOG(10)
If I wanted the log base 2, I would have divided the LOG of the number by the LOG of 2.
Log_Base_2 = LOG(Number) / LOG(2)
how to calculate amount of zeroes? - Neo - 01-16-2004
I used a similar algorithm to determine the size of a Big Integer (BigInt library).
For numbers, you could do like:
Code:
n& = 10000
PRINT "Tenth power:"; LOG(n&) / LOG(10)
PRINT "Note that 10 ^"; LOG(n&) / LOG(10); " is"; n&But since my BigIntegers were strings, I was able to do:
Code:
n$ = "10000"
z& = 32768
PRINT "Tenth power that comes beneath:"; LEN(n$) - 1
PRINT "Note that 10 ^"; LEN(n$) - 1; " has the same amount of numbers as"; z&So if you want the INT(LOG), you can also do this with numbers:
Code:
n& = 10000
PRINT "Tenth power that comes beneath:"; LEN(STR$(n&)) - 2
PRINT "10 ^"; LEN(STR$(n&)) - 2;" has the same amount of numbers as"; n&I don't know which variant is faster, the LOG(n) / LOG(10) variant or the LEN(STR$(n)) - 2 variant, which is used for the rounded logarithm.
how to calculate amount of zeroes? - Lachie Dazdarian - 01-16-2004
Input a
If a=10 or a=20 or a=30 or a=40 or a=50 or a=60 or a=70 or a=80 or a=90 or a=100 or a=110 or....
Never mind...
how to calculate amount of zeroes? - Neo - 01-16-2004
Are you going to do the same as rel?
j/k :lol:
how to calculate amount of zeroes? - Agamemnus - 01-16-2004
Thanks. I just wasted 256 bytes and used a certain array though. Faster I think. I am wasteful.