Я возился с Python, пытаясь практиковать мои алгоритмы сортировки и узнал что-то интересное.
У меня есть три разных фрагмента данных:
- x = количество номеров для сортировки
- y = диапазон чисел (все случайные сгенерированные int)
- z = общее время сортировки
Когда:
x = 100000 и
y = (0,100000), затем
z = 0,94182094911 с
Когда:
x = 100000 и
y = (0,100), затем
z = 12,4218382537 с
Когда:
x = 100000 и
y = (0,10), затем
z = 110,267447809 сек.
Любые идеи?
код:
import time
import random
import sys
#-----Function definitions
def quickSort(array): #random pivot location quicksort. uses extra memory.
smaller = []
greater = []
if len(array) <= 1:
return array
pivotVal = array[random.randint(0, len(array)-1)]
array.remove(pivotVal)
for items in array:
if items <= pivotVal:
smaller.append(items)
else:
greater.append(items)
return concat(quickSort(smaller), pivotVal, quickSort(greater))
def concat(before, pivot, after):
new = []
for items in before:
new.append(items)
new.append(pivot)
for things in after:
new.append(things)
return new
#-----Variable definitions
list = []
iter = 0
sys.setrecursionlimit(20000)
start = time.clock() #start the clock
#-----Generate the list of numbers to sort
while(iter < 100000):
list.append(random.randint(0,10)) #modify this to change sorting speed
iter = iter + 1
timetogenerate = time.clock() - start #current timer - last timer snapshot
#-----Sort the list of numbers
list = quickSort(list)
timetosort = time.clock() - timetogenerate #current timer - last timer snapshot
#-----Write the list of numbers
file = open("C:\output.txt", 'w')
for items in list:
file.write(str(items))
file.write("\n")
file.close()
timetowrite = time.clock() - timetosort #current timer - last timer snapshot
#-----Print info
print "time to start: " + str(start)
print "time to generate: " + str(timetogenerate)
print "time to sort: " + str(timetosort)
print "time to write: " + str(timetowrite)
totaltime = timetogenerate + timetosort + start
print "total time: " + str(totaltime)
------------------- пересмотренный НОВЫЙ код ------------------------- ---
def quickSort(array): #random pivot location quicksort. uses extra memory.
smaller = []
greater = []
equal = []
if len(array) <= 1:
return array
pivotVal = array[random.randint(0, len(array)-1)]
array.remove(pivotVal)
equal.append(pivotVal)
for items in array:
if items < pivotVal:
smaller.append(items)
elif items > pivotVal:
greater.append(items)
else:
equal.append(items)
return concat(quickSort(smaller), equal, quickSort(greater))
def concat(before, equal, after):
new = []
for items in before:
new.append(items)
for items in equal:
new.append(items)
for items in after:
new.append(items)
return new