DNA to RNA Transcription

Build an RNA string by replacing every DNA character with its partner. Use this complete mapping: A → U, C → G, G → C, T → A. Preserve the original order. No biology knowledge is needed.

Implement dna_to_rna(dna).

Input

dna: The DNA string to transform.

Output

Return the transformed string. Empty input returns an empty string.

Restricciones

0 ≤ DNA length ≤ 100,000. Characters are uppercase A, C, G, or T.

Ejemplos

Entrada:
dna = "ACGT"

Salida esperada:
expected = "UGCA"

Entrada:
std::string dna = "ACGT";

Salida esperada:
std::string expected = "UGCA";

Entrada:
string dna = "ACGT";

Salida esperada:
string expected = "UGCA";

Entrada:
dna = ""

Salida esperada:
expected = ""

Entrada:
std::string dna = "";

Salida esperada:
std::string expected = "";

Entrada:
string dna = "";

Salida esperada:
string expected = "";

Referencias

Este reto está adaptado para CodeUtility. Sigue el enunciado y las restricciones indicadas arriba.

• Exercism: RNA Transcription