Fix: NumberFormatException with non-ASCII Unicode digits in MyAtoi (#7231)

Fix myAtoi handling of non-ASCII Unicode digits

src/main/java/com/thealgorithms/strings/MyAtoi.java

@@ -45,7 +45,9 @@ public final class MyAtoi {
         int number = 0;
         while (index < length) {
             char ch = s.charAt(index);
-            if (!Character.isDigit(ch)) {
+
+            // Accept only ASCII digits
+            if (ch < '0' || ch > '9') {
                 break;
             }