Hamming Distance

Compare two DNA strings position by position and count the differences. Only characters at the same position are compared; do not insert, delete, or shift characters. No biology knowledge is needed.

Implement hamming_distance(first, second).

Input

first: The first DNA string.

second: The equal-length second DNA string.

Output

Return the number of positions with different characters.

Contraintes

Both strings have the same length, from 0 to 100,000. Characters are uppercase A, C, G, or T.

Exemples

Entrée :
first = "ACCT"
second = "AGCA"

Sortie attendue :
expected = 2

Entrée :
std::string first = "ACCT";
std::string second = "AGCA";

Sortie attendue :
long long expected = 2;

Entrée :
string first = "ACCT";
string second = "AGCA";

Sortie attendue :
long expected = 2;

Entrée :
first = "GATT"
second = "GATT"

Sortie attendue :
expected = 0

Entrée :
std::string first = "GATT";
std::string second = "GATT";

Sortie attendue :
long long expected = 0;

Entrée :
string first = "GATT";
string second = "GATT";

Sortie attendue :
long expected = 0;

Références

Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.

• Exercism: Hamming