1export function levenshtein(a, b) {
2    if (a.length === 0)
3        return b.length;
4    if (b.length === 0)
5        return a.length;
6    const matrix = [];
7    let i;
8    for (i = 0; i <= b.length; i++) {
9        matrix[i] = [i];
10    }
11    let j;
12    for (j = 0; j <= a.length; j++) {
13        matrix[0][j] = j;
14    }
15    for (i = 1; i <= b.length; i++) {
16        for (j = 1; j <= a.length; j++) {
17            if (b.charAt(i - 1) === a.charAt(j - 1)) {
18                matrix[i][j] = matrix[i - 1][j - 1];
19            }
20            else {
21                if (i > 1 &&
22                    j > 1 &&
23                    b.charAt(i - 2) === a.charAt(j - 1) &&
24                    b.charAt(i - 1) === a.charAt(j - 2)) {
25                    matrix[i][j] = matrix[i - 2][j - 2] + 1;
26                }
27                else {
28                    matrix[i][j] = Math.min(matrix[i - 1][j - 1] + 1, Math.min(matrix[i][j - 1] + 1, matrix[i - 1][j] + 1));
29                }
30            }
31        }
32    }
33    return matrix[b.length][a.length];
34}
35