diff --git a/.vscode/settings.json b/.vscode/settings.json
index 2f4c92279..3b6f8cadb 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -15,4 +15,11 @@
     "[javascriptreact]": {
         "editor.defaultFormatter": "esbenp.prettier-vscode"
     },
+    "[java]": {
+    "spotlessGradle.format.enable": true,
+    "editor.defaultFormatter": "richardwillis.vscode-spotless-gradle",
+    "editor.codeActionsOnSave": {
+      "source.fixAll.spotlessGradle": true
+    },
+  }
 }
diff --git a/lesson_13/maps_ts/src/lesson13.ts b/lesson_13/maps_ts/src/lesson13.ts
index 5207487e2..be8606319 100644
--- a/lesson_13/maps_ts/src/lesson13.ts
+++ b/lesson_13/maps_ts/src/lesson13.ts
@@ -3,5 +3,17 @@
  * https://leetcode.com/problems/permutation-difference-between-two-strings
  */
 export function findPermutationDifference(s: string, t: string): number {
-  return 0;
+  const map = new Map<string, number>();
+
+  for (let i = 0; i < t.length; i++) {
+    map.set(t[i], i);
+  }
+
+  let difference = 0;
+  for (let i = 0; i < s.length; i++) {
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    difference += Math.abs(i - map.get(s[i])!);
+  }
+
+  return difference;
 }