問題
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.
制約
Both strings have the same length, from 0 to 100,000. Characters are uppercase A, C, G, or T.
例
例 1
入力：
first = "ACCT"
second = "AGCA"
期待される出力：
expected = 2入力：
std::string first = "ACCT";
std::string second = "AGCA";
期待される出力：
long long expected = 2;入力：
string first = "ACCT";
string second = "AGCA";
期待される出力：
long expected = 2;解説
The second position is C versus G and the fourth is T versus A. The first and third match: two differences.
例 2
入力：
first = "GATT"
second = "GATT"
期待される出力：
expected = 0入力：
std::string first = "GATT";
std::string second = "GATT";
期待される出力：
long long expected = 0;入力：
string first = "GATT";
string second = "GATT";
期待される出力：
long expected = 0;解説
All four positions match, so no differences are counted.
参考資料
この課題はCodeUtility用に調整されています。上記の説明と制約に従ってください。