feat: kata/help-bob-count-letters-and-digits (#786)

* docs: kata description

* feat: kata/help-bob-count-letters-and-digits

---------

Co-authored-by: ParanoidUser <5120290+ParanoidUser@users.noreply.github.com>

Author: github-actions[bot]

kata/7-kyu/help-bob-count-letters-and-digits/README.md

@@ -0,0 +1,14 @@
+# [Help Bob count letters and digits.](https://www.codewars.com/kata/help-bob-count-letters-and-digits "https://www.codewars.com/kata/5738f5ea9545204cec000155")
+
+Bob is a lazy man.
+
+He needs you to create a method that can determine how many ```letters``` (both uppercase and lowercase **ASCII** letters) and ```digits```
+are in a given string.
+
+Example:
+
+"hel2!lo" --> 6
+
+"wicked .. !" --> 6
+
+"!?..A" --> 1

kata/7-kyu/help-bob-count-letters-and-digits/main/Kata.java

@@ -0,0 +1,5 @@
+interface Kata{
+  static int countLettersAndDigits(String input){
+    return input.replaceAll("[^a-zA-Z\\d]+", "").length();
+  }
+}

kata/7-kyu/help-bob-count-letters-and-digits/test/CountLettersAndDigitsTest.java

@@ -0,0 +1,22 @@
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class CountLettersAndDigitsTest {
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      '', 0
+      ?, 0
+      1, 1
+      hel2!lo, 6
+      n!!_ice!!123, 7
+      aBcDeFg090, 10
+      12345f%%%t5t&/6, 10
+      u_n_d_e_r__S_C_O_R_E, 10
+      """)
+  void sample(String s, int expected) {
+    assertEquals(expected, Kata.countLettersAndDigits(s));
+  }
+}

kata/7-kyu/index.md

@@ -236,6 +236,7 @@
 - [Harvest Festival](harvest-festival "606efc6a9409580033837dfb")
 - [Hëävÿ Mëtäl Ümläüts](heavy-metal-umlauts "57d4e99bec16701a67000033")
 - [Hello World - Without Strings](hello-world-without-strings "584c7b1e2cb5e1a727000047")
+- [Help Bob count letters and digits.](help-bob-count-letters-and-digits "5738f5ea9545204cec000155")
 - [Help Suzuki complete his chores!](help-suzuki-complete-his-chores "584dc1b7766c2bb158000226")
 - [Help Suzuki rake his garden!](help-suzuki-rake-his-garden "571c1e847beb0a8f8900153d")
 - [Help the Fruit Guy](help-the-fruit-guy "557af4c6169ac832300000ba")