The task is:
A non-empty zero-indexed string S is given. String S consists of N characters from the set of upper-case English letters A, C, G, T.
<
This is my JavaScript solution that got 100% across the board on Codility:
function solution(S, P, Q) {
let total = [];
let min;
for (let i = 0; i < P.length; i++) {
const substring = S.slice(P[i], Q[i] + 1);
if (substring.includes('A')) {
min = 1;
} else if (substring.includes('C')) {
min = 2;
} else if (substring.includes('G')) {
min = 3;
} else if (substring.includes('T')) {
min = 4;
}
total.push(min);
}
return total;
}