Problème
For each requested pattern, decide whether it appears as a contiguous substring anywhere in the shared text. Patterns may overlap and may repeat. Return results in the original query order. The limits require an approach that can handle many patterns efficiently.
Implement find_many_patterns(text, patterns).
Input
text: The text searched by every query.
patterns: The patterns, in query order.
Output
Return YES for each occurring pattern and NO for each absent one.
Contraintes
1…100,000 text characters. 1…100,000 nonempty patterns, with total length at most 500,000. All characters are lowercase a–z.
Exemples
Entrée :
text = "bananas"
patterns = ["ana", "apple", "nas"]
Sortie attendue :
expected = ["YES", "NO", "YES"]Entrée :
std::string text = "bananas";
std::vector<std::string> patterns = {"ana", "apple", "nas"};
Sortie attendue :
std::vector<std::string> expected = {"YES", "NO", "YES"};Entrée :
string text = "bananas";
string[] patterns = new string[] {"ana", "apple", "nas"};
Sortie attendue :
string[] expected = new string[] {"YES", "NO", "YES"};Explication
Ana appears starting at position 2 and nas at position 5 (positions start at 1 here). Apple never appears.
Entrée :
text = "aaaa"
patterns = ["aa", "aaaaa", "aa"]
Sortie attendue :
expected = ["YES", "NO", "YES"]Entrée :
std::string text = "aaaa";
std::vector<std::string> patterns = {"aa", "aaaaa", "aa"};
Sortie attendue :
std::vector<std::string> expected = {"YES", "NO", "YES"};Entrée :
string text = "aaaa";
string[] patterns = new string[] {"aa", "aaaaa", "aa"};
Sortie attendue :
string[] expected = new string[] {"YES", "NO", "YES"};Explication
Aa occurs despite overlapping matches. Five a characters cannot fit in a four-character text. The repeated aa query receives the same answer.
Comment l'aborder
Essayez d'abord seul, puis ouvrez les indices un par un.
Indice 1
Many patterns can share work, so avoid searching the text separately for each query.
Indice 2
Build one structure that stores all patterns and scan the text once, advancing matches as characters arrive.
Indice 3
Be careful to report repeated patterns in query order, and let overlapping matches count independently.
Complexité attendue
O(text length + total pattern length) time, O(total pattern length) extra space
Références
Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.