Finding longest substring in alphabetical order

Question

EDIT: I am aware that a question with similar task was already asked in SO but I\'m interested to find out the problem in this specific piece of code. I am

Answer 1

Simple and easy to understand:

s = "abcbcd"    #The original string

l = len(s)    #The length of the original string

maxlenstr = s[0]    #maximum length sub-string, taking the first letter of original string as value.

curlenstr = s[0]    #current length sub-string, taking the first letter of original string as value.

for i in range(1,l):    #in range, the l is not counted. 

    if s[i] >= s[i-1]:    #If current letter is greater or equal to previous letter,
        curlenstr += s[i] #add the current letter to current length sub-string
    else:        
        curlenstr = s[i]  #otherwise, take the current letter as current length sub-string

    if len(curlenstr) > len(maxlenstr): #if current cub-string's length is greater than max one,
            maxlenstr = curlenstr;      #take current one as max one.

print("Longest substring in alphabetical order is:", maxlenstr)