feat: adds amiyah jones' lesson 13.java and ts file

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

@@ -1,12 +1,23 @@
 package com.codedifferently.lesson13;
 
+import java.util.HashMap;
+
 public class Lesson13 {
 
-  /**
-   * Provide the solution to LeetCode 3146 here:
-   * https://leetcode.com/problems/permutation-difference-between-two-strings
-   */
   public int findPermutationDifference(String s, String t) {
-    return 0;
+    var charIndexMap = new HashMap<Character, Integer>();
+
+    int totalDifference = 0;
+
+    for (int sIndex = 0; sIndex < s.length(); sIndex++) {
+      charIndexMap.put(s.charAt(sIndex), sIndex);
+    }
+
+    for (int tIndex = 0; tIndex < t.length(); tIndex++) {
+      int indexInS = charIndexMap.get(t.charAt(tIndex));
+      totalDifference += Math.abs(indexInS - tIndex);
+    }
+
+    return totalDifference;
   }
 }

lesson_13/maps_ts/src/lesson13.ts

@@ -1,7 +1,19 @@
-/**
- * Provide the solution to LeetCode 3146 here:
- * https://leetcode.com/problems/permutation-difference-between-two-strings
- */
 export function findPermutationDifference(s: string, t: string): number {
-  return 0;
+    const charPositionMap = new Map<string, number>();
+
+    let totalDifference = 0;
+
+    for (let sIndex = 0; sIndex < s.length; sIndex++) {
+      charPositionMap.set(s.charAt(sIndex), sIndex)
+    }
+
+    for (let tIndex = 0; tIndex < t.length; tIndex++) {
+      const indexInS = charPositionMap.get(t.charAt(tIndex));
+
+      if (indexInS != undefined) {
+        totalDifference += Math.abs(indexInS - tIndex);
+      }
+    }
+
+    return totalDifference;
 }