★ Efficient algorithm exhausts all upper and lower case forms of a string

jk66255

Such as the string 'aa', there are aa, aA, Aa, AA

To consider the case of non-English characters, test the string:
abcd
ab1d
1111

No recursion.

mtss123

Binary means that each digit is case-sensitive, looping from 0 to 2 ^ n.
(Meet non-letter marks, skip a paragraph more)

jk66255

I think so too, how do non-letters jump?

dylnnet

What does it do?

mtss123

Like ab1d
0000
0001
Then go directly to
0100
...
It can also be regarded as removing one, probably thinking ;)