Price fraction
A friend of mine runs a Pharmacy. He has a specialised rounding function in his Dispensary application which receives a decimal value of currency and forces it to a standard value. This value is regulated by a government department.
You are encouraged to solve this task according to the task description, using any language you may know.
Task: Given a floating point value between 0.00 and 1.00, rescale according to the following table:
>= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00
BASIC
This could also be done by building an array, but I felt that this was simpler.
<lang qbasic>DECLARE FUNCTION PriceFraction! (price AS SINGLE)
RANDOMIZE TIMER DIM x AS SINGLE x = RND PRINT x, PriceFraction(x)
FUNCTION PriceFraction! (price AS SINGLE)
'returns price unchanged if invalid value
SELECT CASE price
CASE IS < 0!
PriceFraction! = price
CASE IS < .06
PriceFraction! = .1
CASE IS < .11
PriceFraction! = .18
CASE IS < .16
PriceFraction! = .26
CASE IS < .21
PriceFraction! = .32
CASE IS < .26
PriceFraction! = .38
CASE IS < .31
PriceFraction! = .44
CASE IS < .36
PriceFraction! = .5
CASE IS < .41
PriceFraction! = .54
CASE IS < .46
PriceFraction! = .58
CASE IS < .51
PriceFraction! = .62
CASE IS < .56
PriceFraction! = .66
CASE IS < .61
PriceFraction! = .7
CASE IS < .66
PriceFraction! = .74
CASE IS < .71
PriceFraction! = .78
CASE IS < .76
PriceFraction! = .82
CASE IS < .81
PriceFraction! = .86
CASE IS < .86
PriceFraction! = .9
CASE IS < .91
PriceFraction! = .94
CASE IS < .96
PriceFraction! = .98
CASE IS < 1.01
PriceFraction! = 1!
CASE ELSE
PriceFraction! = price
END SELECT
END FUNCTION</lang>
Sample outputs (run 5 times):
.7388727 .82 .8593103 .9 .826687 .9 .3444635 .5 .0491907 .1
Clipper
<lang dbase>FUNCTION PriceFraction( npQuantDispensed )
LOCAL aPriceFraction := { {0,.06,.1},;
{.06,.11,.18}, ;
{.11,.16,.26}, ;
{.16,.21,.32}, ;
{.21,.26,.38}, ;
{.26,.31,.44}, ;
{.31,.36,.5}, ;
{.36,.41,.54}, ;
{.41,.46,.58}, ;
{.46,.51,.62}, ;
{.51,.56,.66}, ;
{.56,.61,.7}, ;
{.61,.66,.74}, ;
{.66,.71,.78}, ;
{.71,.76,.82}, ;
{.76,.81,.86}, ;
{.81,.86,.9}, ;
{.86,.91,.94}, ;
{.91,.96,.98} }
LOCAL nResult
LOCAL nScan
IF npQuantDispensed = 0
nResult = 0
ELSEIF npQuantDispensed >= .96
nResult = 1
ELSE
nScan := ASCAN( aPriceFraction, ;
{ |aItem| npQuantDispensed >= aItem[ 1 ] .AND.;
npQuantDispensed < aItem[ 2 ] } )
nResult := aPriceFraction[ nScan ][ 3 ]
END IF
RETURN nResult</lang>
Oz
Using a for-loop with return and a default value for values >= 1.01. For out-of-range input, a "failed value" is returned, i.e. a value that throws an exception when it is accessed.
<lang oz>fun {PriceFraction X}
OutOfRange = {Value.failed outOfRange(X)}
in
for Limit#Result in
[0.00#OutOfRange
0.06#0.10 0.11#0.18 0.16#0.26 0.21#0.32 0.26#0.38 0.31#0.44 0.36#0.5
0.41#0.54 0.46#0.58 0.51#0.62 0.56#0.66 0.61#0.70 0.66#0.74 0.71#0.78
0.76#0.82 0.81#0.86 0.86#0.90 0.91#0.94 0.96#0.98 1.01#1.00
]
return:Return
default:OutOfRange
do
if X < Limit then {Return Result} end
end
end</lang>
Python
Using the bisect standard module.
<lang python>>>> import bisect >>> def pricerounder(pricein): cin = [0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01] cout = [0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00] return cout[ bisect.bisect_right(cin, pricein) ]</lang>
When dealing with money it is good to think about possible loss of precision. If we change the units to be integer cents we could use the following exact routine: <lang python>>>> import bisect >>> _cin = [ 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96, 101] >>> _cout = [10, 18, 26, 32, 38, 44, 50, 54, 57, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100] >>> def centsrounder(centsin): return _cout[ bisect.bisect_right(_cin, centsin) ]</lang> Other options are to use the fractions or decimals modules for calculating money to a known precision.