for (let j = 1; j <= b.length; j += 1) {
for (let i = 1; i <= a.length; i += 1) {
const indicator = a[i - 1] === b[j - 1] ? 0 : 1;

distanceMatrix[j][i] = Math.min(
distanceMatrix[j][i - 1] + 1, // deletion
…