[Tutor] how to find the maximum length substring with equal 'a' and 'b' ?

[Steven D'Aprano]

On Mon, Apr 07, 2014 at 02:27:55AM +0800, Arup Rakshit wrote:

> Suppose, if I have the string 'aababbb', I want to get the output as 
> 'aababb'. I want the output in time complexity O(N) and space 
> complexity O(1). when input string is 'abababa', output should be same 
> as input.

What is your question about? Are you having trouble with learning 
Python, or about the algorithm?

If you tell us the algorithm to use, we can help you with learning 
Python. This sounds like homework. Can you show us what work you have 
already done?

In your first example, your output has 3 a's and 3 b's, but your second 
example doesn't have equal a's and b's. You have:

input abababa (4 a's and 3 b's)

so the output should be ababab, not abababa.



-- 
Steven