KMP inverted clear solution for Long Non Repeat by veky - python coding challenges

Enable Javascript in your browser and then refresh this page, for a much enhanced experience.

KMP inverted solution in Clear category for Long Non Repeat by veky

def intervals(line):
    last = {}
    start = end = 0
    for i, letter in enumerate(line):
        end += 1
        if letter in last and start <= last[letter]:
            start = last[letter] + 1
        yield line[start:end]
        last[letter] = i


def non_repeat(line):
    return max(intervals(line), key=len, default='')

Aug. 12, 2017

Comments:

Nep on Aug. 16, 2018, 6 p.m.
nice)

vadim.kashko on April 10, 2019, 7:30 a.m.
good)

Little+cheng on Aug. 19, 2019, 4:20 a.m.
Excellent！I alse use dict, but it's not as simple as yours.Your codes inspired me alot! Here are my codes. <pre class='brush: python'>def non_repeat(line): if len(line) == 0 or len(line)==1: return line l = '' Dict = {} repeat = 0 while len(line)>1: for i in line: if i not in l: l += i elif i in l: repeat = l.index(i)+1 break Dict[l]=len(l) line = line[((len(l),repeat)[bool(repeat)]):] l = '' return max(Dict,key=Dict.get) </pre>

veky on Aug. 19, 2019, 4:37 a.m.
There are many horrible things about your code. :-P Here are some: <ul> <li>Naming a dictionary you use for some particular purpose `Dict` is the same as naming your dog Dog. You don't call `repeat` Bool, you don't call `i` Int, and you don't call `line` Str, right? You give them semantic names. So give your dict a semantic name too.</li> <li>In fact, your `repeat` isn't a bool, and your `i` is not an int. I really don't object to one-letter names, but if you're going to use `i`, it better be an int. :-o</li> <li>Isn't `len(line) < 2` a simpler way to write your line 2? :-] But really, I don't see what's so special about short lines. You just need to initialize your structures a bit more carefully.</li> <li>`if i not in l: spam` and then `elif i in l: eggs`. Aargh. Wouldn't it be better to write `if i in l: eggs` and then `else: spam`? Of course, actually it's something like `if letter in appeared`. And it would be much better to use EAFP: `try: repeat = l.index(i) + 1` and then `except ValueError: l += i`. </li> <li>Your line 15 is an abomination. Sometimes an `if` is really the one obvious way to do it. Or if you really want to be fancy, how about `line = line[repeat or len(l):]`? :-)</li> </ul>

Little+cheng on Aug. 20, 2019, 2:38 a.m.
Thank you very much! I am a beginner in python,your advice is very helpful to me.It's so cool: <pre class='brush: python'>try: repeat = l.index(i) + 1 except ValueError: l += i </pre> I will pay more attention to details in naming and optimizing my structures!:-)

bsquare on Aug. 23, 2019, 1:47 p.m.
Great with the generator ;)

viktor.chyrkin on Oct. 9, 2021, 3:40 p.m.
nice nice nice nice nice nice nice nice

veky on Oct. 10, 2021, 5:17 a.m.
Any reason for writing this 8 times? :-P

viktor.chyrkin on Oct. 12, 2021, 1:10 a.m.
ummmmm... no?

veky on Oct. 12, 2021, 5:39 a.m.
Great, from 8 `nice`s we're down to 5 `m`s. The next, I guess, is `!!!`, then `??`, then `,`, then `.`, then

veky on Oct. 27, 2022, 1:32 a.m.
... or just a +. Thanks. :-D

Strings Theory

0 %

You ClassRoom Demo is Ready With the new tool CheckiO ClassRoom, you will be able to analyze your students' progress, have your own leaderboard, change missions order on the map, and so on.