Problème
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.
Contraintes
0 ≤ text length ≤ 100,000. Input contains printable ASCII characters. Only letters A–Z and a–z count.
Exemples
Entrée :
text = "The quick brown fox jumps over the lazy dog."
Sortie attendue :
expected = TrueEntrée :
std::string text = "The quick brown fox jumps over the lazy dog.";
Sortie attendue :
bool expected = true;Entrée :
string text = "The quick brown fox jumps over the lazy dog.";
Sortie attendue :
bool expected = true;Explication
Every letter from a through z appears at least once. Capital T counts as t.
Entrée :
text = "abcdefghijklmnopqrstuvwxy"
Sortie attendue :
expected = FalseEntrée :
std::string text = "abcdefghijklmnopqrstuvwxy";
Sortie attendue :
bool expected = false;Entrée :
string text = "abcdefghijklmnopqrstuvwxy";
Sortie attendue :
bool expected = false;Explication
This text contains a through y, but it has no z. One missing letter makes it false.
Comment l'aborder
Essayez d'abord seul, puis ouvrez les indices un par un.
Indice 1
Normalize the text so letter case does not matter.
Indice 2
Track which of the 26 letters have appeared at least once.
Indice 3
Ignore every non-letter character completely, including spaces and punctuation.
Complexité attendue
O(n) time, O(1) extra space
Références
Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.