add: v1.0.0

README.md

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+[https://en.wikipedia.org/wiki/Damerau–Levenshtein_distance](https://en.wikipedia.org/wiki/Damerau–Levenshtein_distance)

damerauLevenshtein.ts

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+export function damerauLevenshtein(s1: string, s2: string): number {
+  const s1len = s1.length;
+  const s2len = s2.length;
+  const matrix: number[][] = Array.from({ length: s1len + 1 }, () => new Array(s2len + 1).fill(0));
+
+  for (let i: number = 1; i <= s1len; i++) {
+    matrix[i][0] = i;
+  }
+
+  for (let j: number = 1; j <= s2len; j++) {
+    matrix[0][j] = j;
+  }
+
+  for (let i: number = 1; i <= s1len; i++) {
+    for (let j: number = 1; j <= s2len; j++) {
+      if (s1[i - 1] === s2[j - 1]) {
+        matrix[i][j] = matrix[i - 1][j - 1];
+      } else {
+        matrix[i][j] = 1 + Math.min(matrix[i - 1][j], matrix[i][j - 1], matrix[i - 1][j - 1]);
+        if (i > 1 && j > 1 && s1[i - 1] === s2[j - 2] && s1[i - 2] === s2[j - 1]) {
+          matrix[i][j] = Math.min(matrix[i][j], matrix[i - 2][j - 2] + 1);
+        }
+      }
+    }
+  }
+  return matrix[s1len][s2len];
+}
+
+export default damerauLevenshtein;