1.冒泡算法
list = [1, 5, 2, 6, 9, 3, 4, 0]
print(len(list)) # 8
conunt = 1
while conunt < len(list):
for i in range(len(list) - conunt):
if list[i + 1] <= list[i]:
list[i], list[i+1] = list[i+1], list[i]
conunt += 1
print(list)
2.二分查找法
# 二分法查找一个数在不在列表中
lst = [11, 22, 33, 44, 55, 66, 77, 88]
# 方法一循环
n = 33
left = 0
right = len(lst) - 1
count = 1
while left <= right:
middle = (left + right) // 2
if n < lst[middle]:
right = middle - 1
elif n > lst[middle]:
left = middle + 1
else:
print("%s在列表中的下标是%d查找次数%d" % (n, middle, count))
break
count += 1
else:
print("%s不在列表lst中" % n)
# 方法二尾递归
def binary_search(n,left=0, right=len(lst)-1, count1=1):
middle = (left + right) // 2
# count1 += 1
if left <= right:
if n < lst[middle]:
right = middle - 1
elif n > lst[middle]:
left = middle + 1
else:
return "%s在列表中的下标是%d查找次数%d" % (n, middle, count1)
return binary_search(n,left, right, count1+1)
return "%s不在列表lst中" % n
res = binary_search(44)
print(res)
# 方法三切片+尾递归
def binary_search(n, lst):
left = 0
right = len(lst) - 1
if left > right:
return "%s不在列表lst中" % n
middle = (left + right) // 2
if n < lst[middle]:
lst = lst[:middle]
elif n > lst[middle]:
lst = lst[middle+1:]
else:
return "%s在列表中" % n
return binary_search(n, lst)
res = binary_search(11, lst)
print(res)