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Bucketsort (view source)

Revision as of 14:04, 17 March 2018

2,893 bytes added ,  6 years ago
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(Created page with "=={{header|QB64}}== <lang B64>REDIM a(0 TO 9999) AS STRING FOR z& = LBOUND(a) TO UBOUND(a) a(z&) = CHR$((33 + RND * (256 - 33)) AND 255) NEXT BucketSort a$() FOR u& = LBOU...")
 
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=={{header|QB64}}==
<lang B64>REDIM a(0 TO 9999) AS STRING
'* Complexity Class: O(N^2)
FOR z& = LBOUND(a) TO UBOUND(a)
TYPE MINMaxRec
a(z&) = CHR$((33 + RND * (256 - 33)) AND 255)
min AS LONG
max AS LONG
END TYPE
 
REDIM a(0 TO 1048575) AS DOUBLE
FOR FillArray& = LBOUND(a) TO UBOUND(a)
a(FillArray&) = RND
NEXT
DoRecurse% = -1
BucketSort a$()
DemoOrder& = 1 '* -1 = descending
FOR u& = LBOUND(a$) TO UBOUND(a$)
BucketSort a(), LBOUND(a), UBOUND(a), DemoOrder&, DoRecurse% '* without the recursive initial call, executiom time is FAR slower.
PRINT a$(u&);
 
NEXT
SUB BucketSort (aArray() AS STRINGDOUBLE, start AS LONG, finish AS LONG, order&, recurse%)
DIM BS_Local_NBuckets AS INTEGER
REDIM Bucketcount(0 TO 255) AS LONG
DIM BS_Local_ArrayRange AS DOUBLE
MinAscii% = 255
DIM BS_Local_N AS LONG
MaxAscii% = 0
DIM BS_Local_S AS LONG
Biggest% = LBOUND(BucketCount)
DIM BS_Local_Z AS LONG
FOR scan& = LBOUND(a) TO UBOUND(a)
DIM BS_Local_Remainder AS INTEGER
IF a(scan&) > "" THEN
DIM BS_Local_Index AS INTEGER
ascii% = ASC(a(scan&))
DIM BS_Local_Last_Insert_Index AS LONG
IF ascii% < MinAscii% THEN
DIM BS_Local_Current_Insert_Index AS LONG
MinAscii% = ascii%
DIM BS_Local_BucketIndex AS INTEGER
REDIM BSMMrec AS MINMaxRec
GetMinMaxArray Array(), start, finish, BSMMrec
BS_Local_ArrayRange = Array(BSMMrec.max) - Array(BSMMrec.min)
IF BS_Local_ArrayRange > 0 THEN
BS_Local_NBuckets = 2 * INT(LOG(finish - start + 1) / LOG(2)) + 1
BS_Local_N = (finish - start)
BS_Local_Remainder = BS_Local_N MOD BS_Local_NBuckets
BS_Local_NBuckets = BS_Local_NBuckets - 1
REDIM BS_Buckets_Array(BS_Local_NBuckets, 0 TO (BS_Local_NBuckets * (1 + (BS_Local_N - BS_Local_Remainder) / BS_Local_NBuckets))) AS DOUBLE
REDIM BS_Count_Array(0 TO BS_Local_NBuckets) AS LONG
FOR BS_Local_S = start TO finish
BS_Local_BucketIndex = BS_Local_NBuckets * ((Array(BS_Local_S) - Array(BSMMrec.min)) / BS_Local_ArrayRange)
BS_Buckets_Array(BS_Local_BucketIndex, BS_Count_Array(BS_Local_BucketIndex)) = Array(BS_Local_S)
BS_Count_Array(BS_Local_BucketIndex) = BS_Count_Array(BS_Local_BucketIndex) + 1
NEXT
BS_Local_Last_Insert_Index = start
BS_Local_Current_Insert_Index = start
FOR BS_Local_S = 0 TO BS_Local_NBuckets
IF BS_Count_Array(BS_Local_S) > 0 THEN
BS_Local_Last_Insert_Index = BS_Local_Current_Insert_Index
FOR BS_Local_Z = 0 TO BS_Count_Array(BS_Local_S) - 1
Array(BS_Local_Current_Insert_Index) = BS_Buckets_Array(BS_Local_S, BS_Local_Z)
BS_Local_Current_Insert_Index = BS_Local_Current_Insert_Index + 1
NEXT
IF recurse% THEN
'* Without this, Bucketort() will be much slower
BucketSort Array(), BS_Local_Last_Insert_Index, BS_Local_Current_Insert_Index - 1, order&, 0
ELSE
'* using MergeSort will speed this significantly, however, this will be left as an exercise
'* MergeSort will keep this sorting algorithm quite competitive.
InsertionSort Array(), BS_Local_Last_Insert_Index, BS_Local_Current_Insert_Index - 1, order&
END IF
END IF
IF ascii% > MaxAscii% THEN
MaxAscii% = ascii%
END IF
IF Bucketcount(ascii%) > Bucketcount(Biggest%) THEN
Biggest% = ascii%
END IF
Bucketcount(ascii%) = Bucketcount(ascii%) + 1
END IF
NEXT
PRINT MinAscii%, MaxAscii%
REDIM Buckets(MinAscii% TO MaxAscii%, 0 TO Bucketcount(Biggest%)) AS STRING
REDIM Bucketcount(MinAscii% TO MaxAscii%) AS LONG
FOR scan& = LBOUND(a) TO UBOUND(a)
IF a(scan&) > "" THEN
nthbucket% = ASC(a(scan&))
PRINT nthbucket%
Buckets(nthbucket%, Bucketcount(nthbucket%)) = a(scan&)
Bucketcount(nthbucket%) = Bucketcount(nthbucket%) + 1
END IF
NEXT
xsum& = LBOUND(a)
FOR i% = MinAscii% TO MaxAscii%
EMerge a(), 0, Bucketcount(i%) - 1
FOR j% = 0 TO Bucketcount(i%) - 1
a(xsum&) = Buckets(i%, j%)
xsum& = xsum& + 1
NEXT
ERASE BS_Buckets_Array, BS_Count_Array
NEXT
END IF
ERASE Buckets
ERASE Bucketcount
END SUB
 
SUB EMergeGetMinMaxArray (Arrayarray() AS STRINGDOUBLE, startStart&, finish&, GetMinMaxArray_minmax AS MINMaxRec)
IFn& = finish& - startStart& = 1 THEN
t% = n& - 10000 * (n& \ 10000)
IF Array(start&) > Array(finish&) THEN
IF (t% MOD 2) THEN
SWAP Array(start&), Array(finish&)
GetMinMaxArray_minmax.min = Start&
END IF
GetMinMaxArray_minmax.max = Start&
GetGetMinMaxArray_minmaxArray_i = Start& + 1
ELSE
IF finisharray(Start&) -> startarray(finish& > 1) THEN
GetMinMaxArray_minmax.max = Start&
m& = start& + (finish& - start& + 1) \ 2
EMergeGetMinMaxArray_minmax.min Array(),= start&, mfinish&
ELSE
EMerge Array(), m& + 1, finish&
EfficientMergeGetMinMaxArray_minmax.min Array(), start&, m&,= finish&
GetMinMaxArray_minmax.max = Start&
END IF
GetGetMinMaxArray_minmaxArray_i = Start& + 2
END IF
END SUB
 
WHILE GetGetMinMaxArray_minmaxArray_i < finish&
SUB EfficientMerge (Array() AS STRING, start&, m&, finish&)
IF array(GetGetMinMaxArray_minmaxArray_i) > array(GetGetMinMaxArray_minmaxArray_i + 1) THEN
DIM b(start& TO m&) AS STRING
IF array(GetGetMinMaxArray_minmaxArray_i) > array(GetMinMaxArray_minmax.max) THEN
i& = start&
GetMinMaxArray_minmax.max = GetGetMinMaxArray_minmaxArray_i
j& = m& + 1
END IF
' // copy first half of array a to auxiliary array b%()
IF array(GetGetMinMaxArray_minmaxArray_i + 1) < array(GetMinMaxArray_minmax.min) THEN
DO
GetMinMaxArray_minmax.min = GetGetMinMaxArray_minmaxArray_i + 1
IF i& > m& THEN
EXITEND DOIF
ELSE
IF array(GetGetMinMaxArray_minmaxArray_i + 1) > array(GetMinMaxArray_minmax.max) THEN
b(i&) = Array(i&)
GetMinMaxArray_minmax.max = GetGetMinMaxArray_minmaxArray_i + 1
j& = j& + 1
i&END = i& + 1IF
IF array(GetGetMinMaxArray_minmaxArray_i) < array(GetMinMaxArray_minmax.min) THEN
END IF
GetMinMaxArray_minmax.min = GetGetMinMaxArray_minmaxArray_i
LOOP
i& = start&
j& = m& + 1
k& = start&
' // copy back next-greatest element at each time
 
DO
IF j& > finish& THEN
EXIT DO
ELSE
IF k& < j& THEN
IF b(i&) <= Array(j&) THEN
Array(k&) = b(i&)
i& = i& + 1
ELSE
Array(k&) = Array(j&)
j& = j& + 1
END IF
k& = k& + 1
ELSE
EXIT DO
END IF
END IF
GetGetMinMaxArray_minmaxArray_i = GetGetMinMaxArray_minmaxArray_i + 2
LOOP
' // copy back remaining elements of first half (if any)
WHILE (k& < j&)
Array(k&) = b(i&)
k& = k& + 1
i& = i& + 1
WEND
END SUB
ERASE b
 
SUB InsertionSort (array() AS DOUBLE, start AS LONG, finish AS LONG, order&)
DIM InSort_L_ArrayTemp AS DOUBLE
DIM InSort_L_i AS LONG
DIM InSort_L_j AS LONG
SELECT CASE order&
CASE 1
FOR InSort_L_i = start + 1 TO finish
InSort_L_ArrayTemp = array(InSort_L_i)
InSort_L_j = InSort_L_i - 1
DO UNTIL InSort_L_j < start
IF (InSort_L_ArrayTemp < array(InSort_L_j)) THEN
array(InSort_L_j + 1) = array(InSort_L_j)
InSort_L_j = InSort_L_j - 1
ELSE
EXIT DO
END IF
LOOP
array(InSort_L_j + 1) = InSort_L_ArrayTemp
NEXT
CASE ELSE
FOR InSort_L_i = start + 1 TO finish
InSort_L_ArrayTemp = array(InSort_L_i)
InSort_L_j = InSort_L_i - 1
DO UNTIL InSort_L_j < start
IF (InSort_L_ArrayTemp > array(InSort_L_j)) THEN
array(InSort_L_j + 1) = array(InSort_L_j)
InSort_L_j = InSort_L_j - 1
ELSE
EXIT DO
END IF
LOOP
array(InSort_L_j + 1) = InSort_L_ArrayTemp
NEXT
END SELECT
END SUB
</lang>
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