Разделить слово на части

word = input()
output = []
current_part = ""
 
i = 0
while i < len(word):
    letter = word[i]
    while letter in word[i:] and i < len(word):
        current_part = current_part + word[i]
        i += 1
        continue
    else:
        output.append(current_part)
        current_part = ""
 
print(*output)

from collections import Counter
 
def solution():
    word = input()
    letters = Counter(word)
    result = [[]]
    for letter in word:
        letters[letter] -= 1
        if letters[letter]:
            result[-1].append(letter)
        else:
            if any(letters[c] for c in result[-1]):
                result[-1].append(letter)
            else:
                result[-1].append(letter)
                result.append([])
    print(*map("".join, result))
 
if __name__ == "__main__":
    solution()

from collections import Counter
 
def solution():
    word = input()
    letters = Counter(word)
    result = [[]]
    for letter in word:
        letters[letter] -= 1
        result[-1].append(letter)
        if all(letters[c] == 0 for c in result[-1]):
            result.append([])
    print(*map("".join, result))
 
if __name__ == "__main__":
    solution()

word = input()
output = []
current_part = ""
i = 0
 
while i < len(word):
    letter = word[i]
    while letter in word[i:] and i < len(word):
        current_part = current_part + word[i]
        i += 1
        continue
    else:
        changes = True
        while changes:
            changes = False
            for j in range(1, len(current_part)):
                if i < len(word) and len(current_part) > j:
                    letter = current_part[j]
                    while letter in word[i:] and i < len(word):
                        current_part = current_part + word[i]
                        changes = True
                        i += 1
                        continue
        output.append(len(current_part))
        current_part = ""
 
print(*output)

from collections import Counter
 
def solution():
    word = input()
    letters = Counter(word)  # В среднем O(N) - я думаю, это очевидно (худший случай, когда кривой хеш у строк опустим)
    result = [[]]
    for letter in word:  # O(N) - аналогично
        letters[letter] -= 1
        result[-1].append(letter)
        if all(letters[c] == 0 for c in result[-1]):  # O(M), M <= N
            result.append([])
    # Суммарно, будет не более N частей (result[i]) - O(M) => Общая асимтотика O(N)
    print(*map("".join, result))
 
if __name__ == "__main__":
    solution()

word = 'a'+'b'*1000000 + 'a' +'cc'

word = input()
output = []
i = 0
while i < len(word):
    a = i
    b = word.rfind(word[i])
    j = 1
    if b > a:
        j = a+1
        while j < b:
            t = word.rfind(word[j])
            b = max(b, t)
            j += 1
    output.append(b-a+1)
    i += b-a+1
print(*output)

In [1]: from collections import Counter
    ...:
    ...: def solution(word):
    ...:     letters = Counter(word)
    ...:     result = [[]]
    ...:     for letter in word:
    ...:         letters[letter] -= 1
    ...:         result[-1].append(letter)
    ...:         if all(letters[c] == 0 for c in result[-1]):
    ...:             result.append([])
    ...:     yield from map("".join, result)
    ...:
 
In [2]: word = 'a'+'b'*1000000 + 'a' +'cc'
 
In [3]: timeit solution(word)
464 ns ± 5.04 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)