快速排序
def quick_sort(li, left, right):
if left < right:
mid = partition(li, left, right)
quick_sort(li, left, mid-1) # 递归排列左部分
quick_sort(li, mid+1, right) # 递归排列右部分
# 将列表切割为两段
def partition(li, left, right):
tmp = li[left]
while left < right:
while left < right and li[right] >= tmp:
right -= 1
li[left] = li[right]
while left < right and li[left] <= tmp:
left += 1
li[right] = li[left]
li[left] = tmp
return left
import random
li = list(range(100))
random.shuffle(li)
quick_sort(li, 0, len(li)-1)
print(li)
归并排序
def merge(li, low, mid, high):
# 列表两段有序: [low, mid] [mid+1, high]
i = low
j = mid + 1
li_tmp = []
while i <= mid and j <= high:
if li[i] <= li[j]:
li_tmp.append(li[i])
i += 1
else:
li_tmp.append(li[j])
j += 1
while i <= mid:
li_tmp.append(li[i])
i += 1
while j <= high:
li_tmp.append(li[j])
j += 1
# li_tmp[0:high-low+1] li[low:high+1]
for i in range(low, high+1):
li[i] = li_tmp[i-low]
# li[low:high+1] = li_tmp
def _merge_sort(li, low, high): #排序li的low到high的范围
if low < high:
mid = (low + high) // 2
_merge_sort(li, low, mid)
_merge_sort(li, mid+1, high)
# print(li[low:mid + 1], li[mid + 1:high + 1])
merge(li, low, mid, high)
# print(li[low: high + 1])
li = [10, 4, 6, 3, 8, 2, 5, 7]
_merge_sort(li, 0, len(li)-1)
print(li)
