第七次课课上代码

た入场券 2022-05-14 12:25 154阅读 0赞

时间空间复杂度（例子：1-n求和）

复杂度：[https://blog.csdn.net/hebtu666/article/details/82463970][https_blog.csdn.net_hebtu666_article_details_82463970]

[https://blog.csdn.net/hebtu666/article/details/82465495][https_blog.csdn.net_hebtu666_article_details_82465495]

二分

一个数组查找某个值1 2 3 5 6 7 8 9 10 15 20。。

查找11

Debug（二分）（\#，’’’,打印）

二分：[https://blog.csdn.net/hebtu666/article/details/81410301][https_blog.csdn.net_hebtu666_article_details_81410301]

桶排序 O(N) O(NlogN) O(N^2)

1 10000000

0 1 2 1 2 1 0 1 1

0 1 2 3 4 5 6 7 8

O(e)

1 2 2 3 4 4 5 7 8

排序稳定性

[https://blog.csdn.net/hebtu666/article/details/81434236，排序好好看][https_blog.csdn.net_hebtu666_article_details_81434236]

**5** 4 5 6 7 8

4 5 **5** 6 7 8

一、 50 10

二、 40 5

三、 45 20

四、 40 10

先按后面的数排 三一四二

再按前面的，一、三、四、二

埃氏筛

代码：

>>> a=0  
>>> for i in range(5):  
a+=i

>>> print(a)  
10  
>>> print(o(n))  
Traceback (most recent call last):  
File "<pyshell\#5>", line 1, in <module>  
print(o(n))  
NameError: name 'o' is not defined  
>>> print('o(n)')  
o(n)  
>>> print('o(1)')  
o(1)  
>>> n=int(input())  
5  
>>> l=\[0\]\*n  
>>> l  
\[0, 0, 0, 0, 0\]  
>>> for i in range(n):  
l\[i\]=int(input())

1  
6  
2  
3  
1  
>>> print(sum(l))  
13  
>>> n=int(input())  
5  
SyntaxError: multiple statements found while compiling a single statement  
>>> n=int(input())  
5  
>>> a=0  
>>> for i in range(n):  
a+=int(input())

1  
2  
3  
4  
5  
>>> print(a)  
15  
>>> def f(key,l):  
left,right=0,len(l)-1  
while left<=right:  
mid=int((left+right)/2)  
if key<l\[mid\]:  
right=mid-1  
elif key>l\[mid\]:  
left=mid+1  
else:  
print(mid)  
return  
print(-1)

>>>

[https_blog.csdn.net_hebtu666_article_details_82463970]: https://blog.csdn.net/hebtu666/article/details/82463970
[https_blog.csdn.net_hebtu666_article_details_82465495]: https://blog.csdn.net/hebtu666/article/details/82465495
[https_blog.csdn.net_hebtu666_article_details_81410301]: https://blog.csdn.net/hebtu666/article/details/81410301
[https_blog.csdn.net_hebtu666_article_details_81434236]: https://blog.csdn.net/hebtu666/article/details/81434236