View difference between Paste ID: PjPBZY3H and 33Ybamyp

 class Solution {
     private static final char[][] FAST_MAP = initChar();
-    private static final Map<Character, List<Character>> MAPPING = Map.ofEntries(
+    private static char[][] initChar() {
-        Map.entry('1', List.of()),
+        char[][] result = new char[10][];
-        Map.entry('2', List.of('a', 'b', 'c')),
+        result[0] = new char[]{};
-        Map.entry('3', List.of('d', 'e', 'f')),
+        result[1] = new char[]{};
-        Map.entry('4', List.of('g', 'h', 'i')),
+        result[2] = new char[]{'a', 'b', 'c'};
-        Map.entry('5', List.of('j', 'k', 'l')),
+        result[3] = new char[]{'d', 'e', 'f'};
-        Map.entry('6', List.of('m', 'n', 'o')),
+        result[4] = new char[]{'g', 'h', 'i'};
-        Map.entry('7', List.of('p', 'q', 'r', 's')),
+        result[5] = new char[]{'j', 'k', 'l'};
-        Map.entry('8', List.of('t', 'u', 'v')),
+        result[6] = new char[]{'m', 'n', 'o'};
-        Map.entry('9', List.of('w', 'x', 'y', 'z'))
+        result[7] = new char[]{'p', 'q', 'r', 's'};
-    );
+        result[8] = new char[]{'t', 'u', 'v'};
         result[9] = new char[]{'w', 'x', 'y', 'z'};
         return result;
     }
 
 
     private List<String> result = null;
     public List<String> letterCombinations(String digits) {
         if (digits.isEmpty()) {
             return List.of();
-        MAPPING.get(digits.charAt(index)).forEach(value -> {
+
         result = new ArrayList<>();
         compute(digits, 0, new StringBuilder());
         return result;
-        });
+
 
     private void compute(String digits, int index, StringBuilder stringBuilder) {
         if (index == digits.length()) {
             result.add(stringBuilder.toString());
             return;
         }
 
         for (char value : FAST_MAP[digits.charAt(index) - '0']) {
             stringBuilder.append(value);
             compute(digits, index + 1, stringBuilder);
             stringBuilder.setLength(stringBuilder.length() - 1);
         };
     }
 
 }