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#冒泡排序
def BubbleSort(mylist):
n = len(mylist)
i = 0
j = 0
bExchange = False
for i in range(1, n):
bExchange = False
j = n - 1
while j >= i:
if mylist[j] < mylist[j - 1]:
tmp = mylist[j]
mylist[j] = mylist[j - 1]
mylist[j - 1] = tmp
bExchange = True
j = j - 1
if not bExchange:
break

mylist0 = [11, 10, 4, 2, 1, 55, 99, 102]
BubbleSort(mylist0)
print(mylist0)
......

#快速排序
def Partition(mylist, low, high):
tmp = mylist[low]
while low < high:
while low < high and mylist[high] >= tmp:
high = high - 1
if low < high:
mylist[low] = mylist[high]
low = low + 1
while low < high and mylist[low] <= tmp:
low = low + 1
if low < high:
mylist[high] = mylist[low]
high = high - 1
mylist[low] = tmp
return low
def QuickSort(mylist, low, high):
if low < high:
pivotpos = Partition(mylist, low, high)
QuickSort(mylist, low, pivotpos - 1)
QuickSort(mylist, pivotpos + 1, high)
mylist0 = [11, 10, 3, 12, 33, 1000, 1, 333, -11]
QuickSort(mylist0, 0, len(mylist0) - 1)
print(mylist0)
......

#直接选择排序
def SelectSort(mylist):
size = len(mylist)
i = 0
for i in range(0, size):
k = i
for j in range(i + 1, size):
if mylist[j] < mylist[k]:
k = j

if k != i:
tmp = mylist[i]
mylist[i] = mylist[k]
mylist[k] = tmp

mylist0 = [11, 2, 3, 4, 112, 100]
SelectSort(mylist0)
print(mylist0)
......

#堆排序
def Heapify(mylist, start, end):
left = 0
right = 0
maxv = 0
left = start * 2
right = start * 2 + 1
while left <= end:
maxv = left
if right <= end:
if mylist[left] < mylist[right]:
maxv = right
else:
maxv = left
if mylist[start] < mylist[maxv]:
tmp = mylist[maxv]
mylist[maxv] = mylist[start]
mylist[start] = tmp
start = maxv
else:
break
left = start * 2
right = start * 2 + 1

def BuildHeap(mylist):
size = len(mylist)
i = (size -1) // 2;
while i >= 0:
Heapify(mylist, i, size - 1)
i = i - 1

def HeapSort(mylist):
BuildHeap(mylist)
i = len(mylist) - 1

while i >= 0:
tmp = mylist[0]
mylist[0] = mylist[i]
mylist[i] = tmp

Heapify(mylist, 0, i - ......

先说python
python的random模块提供了多个伪随机数发生器，默认都是用当前时间戳为随机数种子。
下面是该模块几个最常用的函数
random() Return the next random floating point number in the range [0.0, 1.0).
randint(a,b) Return a random integer N such that a <=
N <= b
randrange([start,]stop[,step]) Return a randomly selected element from range(start,
stop, step).
sample(seq,k) Return k length list of unique elements chosen from the sequence seq(从序列中取出k个不重复的值，用起来方便)
uniform(a,b) Return a random real number N such that a<=N<b
choice(seq) Return a random element from the NONE-empty sequence seq,if seq is empty,raises indexerror
seed([x]) 设置随机数发生器的种子值，默认以系统时间为种子，精度应该很高。
mark:python的random模块还提供了高斯分布，正太分布，beta分布等的随机数生成。
import random
random.random()
random.randint(0, 1)
random.choice('abcdefghij')
random.uniform(1, 3)
random.sample([1, 2, 3, 4, 5, 6, 7, 8, 9], 5)
......

def MergeSort(mylist, low, mid, high):
i = low
j = mid + 1
tmp = []

while i <= mid and j <= high:
if mylist[i] <= mylist[j]:
tmp.append(mylist[i])
i = i + 1
else:
tmp.append(mylist[j])
j = j + 1

while i <= mid:
tmp.append(mylist[i])
i = i + 1
while j <= high:
tmp.append(mylist[j])
j = j + 1
for k in range(low, high):
mylist[k] = tmp[k]

mylist0 = [1, 3, 5, 7, 9, 11, 6, 8, 66, 88, 100]
MergeSort(mylist0, 0, 5, len(mylist0) - 1)
print(mylist0)
......

python算法实践3 冒泡排序

python算法实践4 快速排序

python算法实践5 直接选择排序

python算法实践6 堆排序

python,c++,C#随机数生成

python,c++,C#随机数生成

python,c++,C#随机数生成

python,c++,C#随机数生成

python算法实践7 归并排序