Условие
A pangram contains every English letter at least once. Determine whether the text is a pangram. Ignore case, spaces, digits, and punctuation.
Implement pangram_check(text).
Input
text: The text to inspect.
Output
Return true if all 26 letters appear, otherwise false.
Ограничения
0 ≤ text length ≤ 100,000. Input contains printable ASCII characters. Only letters A–Z and a–z count.
Примеры
Ввод:
text = "The quick brown fox jumps over the lazy dog."
Ожидаемый вывод:
expected = TrueВвод:
std::string text = "The quick brown fox jumps over the lazy dog.";
Ожидаемый вывод:
bool expected = true;Ввод:
string text = "The quick brown fox jumps over the lazy dog.";
Ожидаемый вывод:
bool expected = true;Пояснение
Every letter from a through z appears at least once. Capital T counts as t.
Ввод:
text = "abcdefghijklmnopqrstuvwxy"
Ожидаемый вывод:
expected = FalseВвод:
std::string text = "abcdefghijklmnopqrstuvwxy";
Ожидаемый вывод:
bool expected = false;Ввод:
string text = "abcdefghijklmnopqrstuvwxy";
Ожидаемый вывод:
bool expected = false;Пояснение
This text contains a through y, but it has no z. One missing letter makes it false.
Как подступиться
Сначала попробуйте сами, затем открывайте подсказки по одной.
Подсказка 1
Normalize the text so letter case does not matter.
Подсказка 2
Track which of the 26 letters have appeared at least once.
Подсказка 3
Ignore every non-letter character completely, including spaces and punctuation.
Ожидаемая сложность
O(n) time, O(1) extra space
Ссылки
Это задание адаптировано для CodeUtility. Следуйте условию и ограничениям выше.