feat: kata/build-alien-virus-estimator (#717)

* docs: kata description

* docs: sync progress

* feat: kata/build-alien-virus-estimator

---------

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

Author: github-actions[bot]

docs/README.md

@@ -25,7 +25,7 @@ slug.
 
 | [1 kyu](/kata/1-kyu/index.md) | [2 kyu](/kata/2-kyu/index.md) | [3 kyu](/kata/3-kyu/index.md) | [4 kyu](/kata/4-kyu/index.md) | [5 kyu](/kata/5-kyu/index.md) | [6 kyu](/kata/6-kyu/index.md) | [7 kyu](/kata/7-kyu/index.md) | [8 kyu](/kata/8-kyu/index.md) | [beta](/kata/beta/index.md) | [retired](/kata/retired/index.md) |
 |:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:-----------------------------:|:---------------------------:|:---------------------------------:|
-| 0 | 1 | 2 | 26 | 48 | 439 | 600 | 224 | 55 | 82 |
+| 0 | 1 | 2 | 26 | 48 | 439 | 600 | 224 | 56 | 82 |
 
 **Note:** The source code is written in Java 17 and may use language features that are incompatible
 with Java 8, 11.

kata/beta/build-alien-virus-estimator/README.md

@@ -0,0 +1,14 @@
+# [Build Alien Virus Estimator](https://www.codewars.com/kata/build-alien-virus-estimator "https://www.codewars.com/kata/675851e0ebd55559d1082d24")
+
+A deadly alien virus has escaped from a remote swamp lab, where it was first analyzed. You have to determine their count, so that further
+action can be taken. The only catch is that they multiply rapidly.
+
+The crazed professor can only tell you 3 things:
+
+- How many units have escaped
+- By how much they increase every minute
+- How many minutes have passed
+
+You have to return the # of virus units out there. If the # of units is not deterministic, return -1.
+
+Note: The virus count have been referred to as "units".

kata/beta/build-alien-virus-estimator/main/AlienVirusEstimator.java

@@ -0,0 +1,5 @@
+interface AlienVirusEstimator {
+  static long findVirusUnits(long unitsEscaped, long increasePerMinute, long minutesPassed) {
+    return Math.max(--minutesPassed * increasePerMinute + unitsEscaped, -1);
+  }
+}

kata/beta/build-alien-virus-estimator/test/AlienVirusEstimatorTest.java

@@ -0,0 +1,16 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class AlienVirusEstimatorTest {
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      2, 4, 3, 10
+      4, 2, 10, 22
+      7, -5, 8, -1
+      """)
+  void sample(long escaped, long spread, long minutes, long units) {
+    assertEquals(units, AlienVirusEstimator.findVirusUnits(escaped, spread, minutes));
+  }
+}

kata/beta/index.md

@@ -6,6 +6,7 @@
 - [Basic Arabic-To-Roman Numerals (1 to 999)](basic-arabic-to-roman-numerals-1-to-999)
 - [Beginner friendly: remove the letter o](beginner-friendly-remove-the-letter-o)
 - [Brackets Checker](brackets-checker)
+- [Build Alien Virus Estimator](build-alien-virus-estimator)
 # C
 - [CaMeLcAsInG](camelcasing)
 - [Change for pizza](change-for-pizza)