feat: adds lesson_13 Java & TypeScript

Author: TatsuyaRyujin

lesson_13/maps_java/maps_app/src/main/java/com/codedifferently/lesson13/Lesson13.java

@@ -7,6 +7,14 @@ public class Lesson13 {
    * https://leetcode.com/problems/permutation-difference-between-two-strings
    */
   public int findPermutationDifference(String s, String t) {
-    return 0;
+    int total = 0;
+
+    for (int i = 0; i < s.length(); i++) {
+      char ch = s.charAt(i);
+      int idx2 = t.indexOf(ch);
+
+      total += Math.abs(i - idx2);
+    }
+    return total;
   }
 }

lesson_13/maps_ts/src/lesson13.ts

@@ -3,5 +3,13 @@
  * https://leetcode.com/problems/permutation-difference-between-two-strings
  */
 export function findPermutationDifference(s: string, t: string): number {
-  return 0;
+  let total = 0;
+
+  for (let i = 0; i < s.length; i++) {
+    const ch = s.charAt(i);
+    const idx2 = t.indexOf(ch);
+
+    total += Math.abs(i - idx2);
+  }
+  return total;
 }