快速排序:
以列表中的任意一个数为基准(一般选取第一个数),将列表分为左右(前后)两个子列表,左边子列表的数要比基数小,右边的子列表要比基数大,然后继续把左边子列表和右边子列表按同样的方法继续分解、比较,一直分到分无可分位置,然后按照左边子列表比基数小+基数+右边子列表(比基数大)的方式连接起来,最后得到一个有序的数列
import random
import timeit
def randomList(n):
iList = []
for i in range(n):
iList.append(random.randrange(0,1000))
return iList
def bubblesort(iList):
if (len(iList)<=1):
return iList
for i in range(1,len(iList)):
for j in range(0,len(iList)-i):
if(iList[j]>iList[j+1]):
iList[j],iList[j+1] = iList[j+1],iList[j]
return iList
def selectsort(iList):
if(len(iList)<=1):
return iList
for i in range(0,len(iList)-1):
if iList[i] != min(iList[i:]):
minIndex = iList.index(min(iList[i:]))
iList[i],iList[minIndex] = iList[minIndex],iList[i]
return iList
def insetionsort(iList):
if(len(iList)<=1):
return iList
for right in range(1,len(iList)):
target = iList[right]
for left in range(0,right):
if target<=iList[left]:
iList[left+1:right+1] = iList[left:right]
iList[left] = target;
break
return iList
def quicksort(iList):
if(len(iList)<=1):
return iList
left = []
right = []
for i in iList[1:]:
if i<=iList[0]:
left.append(i)
else :
right.append(i)
return quicksort(left)+[iList[0]]+quicksort(right)
if __name__ == "__main__":
iList = randomList(20)
print(iList)
print(quicksort(iList))
#print(timeit.timeit("selectsort(iList)","from _main_ import selectsort,iList",number=100))