Problema
C# records compare by value: two records are equal when all their fields are equal, even if they are different objects. That makes removing duplicates easy.
Each record is written name,city. Trim spaces around both fields; after trimming, two records are equal when both fields match exactly (case matters).
Implement unique_records(records).
Input
records: The records, in order.
Output
Return the distinct records in the order they first appear, written name,city with the trimmed fields.
Restricciones
0 ≤ number of records ≤ 100,000
Each field has 1 to 30 characters and no commas
Ejemplos
Entrada:
records = ["Ada,London", "Lin, Hanoi", "Ada , London"]
Salida esperada:
expected = ["Ada,London", "Lin,Hanoi"]Entrada:
std::vector<std::string> records = {"Ada,London", "Lin, Hanoi", "Ada , London"};
Salida esperada:
std::vector<std::string> expected = {"Ada,London", "Lin,Hanoi"};Entrada:
string[] records = new string[] {"Ada,London", "Lin, Hanoi", "Ada , London"};
Salida esperada:
string[] expected = new string[] {"Ada,London", "Lin,Hanoi"};Explicación
After trimming, the third record equals the first, so it is dropped: ["Ada,London", "Lin,Hanoi"].
Entrada:
records = ["ada,Paris", "Ada,Paris"]
Salida esperada:
expected = ["ada,Paris", "Ada,Paris"]Entrada:
std::vector<std::string> records = {"ada,Paris", "Ada,Paris"};
Salida esperada:
std::vector<std::string> expected = {"ada,Paris", "Ada,Paris"};Entrada:
string[] records = new string[] {"ada,Paris", "Ada,Paris"};
Salida esperada:
string[] expected = new string[] {"ada,Paris", "Ada,Paris"};Explicación
Case matters, so these two records are different: ["ada,Paris", "Ada,Paris"].
Cómo abordarlo
Inténtalo primero por tu cuenta y luego abre las pistas una a una.
Pista 1
Trim both fields before comparing records.
Pista 2
A set of (name, city) pairs remembers which records you have seen.
Pista 3
Output each new record the first time it appears, in input order.
Complejidad esperada
O(total length) time, O(number of records) extra space
Referencias
Este reto está adaptado para CodeUtility. Sigue el enunciado y las restricciones indicadas arriba.