added new algorithms: ParenthesisCheck and StringEqualsHash; edited some comments in other package

src/main/kotlin/other/Euclid.kt

@@ -1,6 +1,7 @@
 package other
 
 /**
+ *
  * Euclid's algorithm for finding the greatest common divisor
  *
  */
@@ -8,9 +9,11 @@ package other
 class Euclid {
 
     /**
+     *
      * finds the greatest common divisor of two numbers
      *
      * @return returns the greatest common divisor
+     *
      */
     fun compute(num1: Int, num2: Int) : Int {
         var copyNum1 = num1

src/main/kotlin/other/LevensteinLength.kt

@@ -3,6 +3,7 @@ package other
 import java.lang.Integer.min
 
 /**
+ *
  * Algorithm for determining the Levenshtein distance
  *
  */
@@ -10,9 +11,11 @@ import java.lang.Integer.min
 class LevenshteinLength {
 
     /**
+     *
      * determines the Levenshtein distance for two strings and returns it
      *
      * @return returns the Levenshtein distance for two strings
+     *
      */
     fun compute(str1: String, str2: String) : Int {
         val matrix = Array(str1.length + 1) {
@@ -39,4 +42,5 @@ class LevenshteinLength {
 
         return matrix[str1.length][str2.length]
     }
+
 }

src/main/kotlin/other/Max.kt

@@ -12,6 +12,7 @@ class Max<T : Comparable<T>> {
     /**
      *
      * @return returns the maximum element from the list
+     *
      */
     fun compute(items: List<T>) : T {
         if (items.isEmpty()) {
@@ -29,6 +30,7 @@ class Max<T : Comparable<T>> {
     /**
      *
      * @return returns the maximum element from the list recursively
+     *
      */
     fun computeRecursive(items: List<T>) : T {
         if (items.size == 1) {

src/main/kotlin/other/Palindrome.kt

@@ -1,6 +1,7 @@
 package other
 
 /**
+ *
  * Algorithm for checking a string for a palindrome
  *
 */
@@ -8,9 +9,11 @@ package other
 class Palindrome(private val text: String) {
 
     /**
+     *
      * checks a string for a palindrome
      *
      * @return returns true if the string is a palindrome
+     *
      */
     fun isYes() = text == text.reversed()
 
@@ -18,6 +21,7 @@ class Palindrome(private val text: String) {
      * checks if a string is not a palindrome
      *
      * @return returns true if the string is not a palindrome
+     *
      */
     fun isNot() = !isYes()
 

src/main/kotlin/other/PalindromeAdvanced.kt

@@ -1,6 +1,7 @@
 package other
 
 /**
+ *
  * Algorithm for checking a string for a palindrome
  *
  */
@@ -8,9 +9,11 @@ package other
 class PalindromeAdvanced(private val text: String) {
 
     /**
+     *
      * checks a string for a palindrome
      *
      * @return returns true if the string is a palindrome
+     *
      */
     fun isYes() : Boolean {
         if (text.length <= 1) {
@@ -25,9 +28,11 @@ class PalindromeAdvanced(private val text: String) {
     }
 
     /**
+     *
      * checks if a string is not a palindrome
      *
      * @return returns true if the string is not a palindrome
+     *
      */
     fun isNot() = !isYes()
 

src/main/kotlin/other/ParenthesisCheck.kt

@@ -0,0 +1,60 @@
+package other
+
+/**
+ *
+ * checks a string for correct placement of parentheses using stack
+ *
+ * ([]) - correctly
+ * ()(){} - correctly
+ * (() - incorrectly
+ * (())[][]}{ - incorrectly
+ *
+ */
+
+class ParenthesisCheck {
+
+    /**
+     *
+     * we use a regular kotlin list to create a stack
+     *
+     * @return returns true if parentheses are correctly spaced otherwise false
+     *
+     */
+    fun check(code: String = defaultCode): Boolean {
+        val stack = mutableListOf<Char>()
+
+        var index = 0
+        while (index < code.length) {
+
+            when (val symbol = code[index]) {
+                '(', '{', '[' -> stack.add(symbol)
+                ')', '}', ']' -> {
+                    val value = bracketRelations[stack.removeLastOrNull()]
+                    if (symbol != value) {
+                        return false
+                    }
+                }
+            }
+
+            index++
+        }
+
+        return true
+    }
+
+    companion object {
+        /**
+         *
+         * correct C program
+         *
+         */
+        private const val defaultCode = """
+            void main() {
+                printf("Hello, World!");
+            }
+        """
+
+        private val bracketRelations = mapOf('(' to ')', '{' to '}', '[' to ']')
+    }
+
+}

src/main/kotlin/other/ReverseArray.kt

@@ -1,9 +1,11 @@
 package other
 
 /**
- * Reverse Array
+ *
+ * reverse array
  *
  * algorithm complexity: n/2 operations
+ *
  */
 
 class ReverseArray<T> {

src/main/kotlin/other/SieveOfEratosthenes.kt

@@ -1,18 +1,22 @@
 package other
 
 /**
+ *
  * The sieve of Eratosthenes allows you to efficiently calculate a series of prime numbers
  *
  * algorithm complexity: nlog(logn) operations
+ *
  */
 
 class SieveOfEratosthenes {
 
     /**
+     *
      * computes a series of primes for the maximum value
      *
-     * @maxNumber - maximum value
-     * @return - returns a list of prime numbers
+     * @param maxNumber - maximum value
+     * @return returns a list of prime numbers
+     *
      */
     fun compute(maxNumber: Int) : List<Int> {
         val numbers = Array(maxNumber + 1) { index -> index >= 2 }

src/main/kotlin/other/StringEqualsHash.kt

@@ -0,0 +1,45 @@
+package other
+
+/**
+ *
+ * comparing two strings with a hash
+ *
+ */
+
+class StringEqualsHash {
+
+    /**
+     *
+     * computes the hash of a string according to the formula:
+     *
+     * hash(abc) = a.code * primeCoefficient⁰ + b.code * primeCoefficient¹ + c.code * primeCoefficient²
+     *
+     * @return returns the hash of the string
+     *
+     */
+    private fun String.hash() : Int {
+        var result = 0
+        var factor = 1
+        forEach { symbol ->
+            result += symbol.code * factor
+            factor *= primeCoefficient
+        }
+        return result.mod(Int.MAX_VALUE)
+    }
+
+    fun equals(source: String, pattern: String) : Boolean =
+        if (source.length != pattern.length) false else source.hash() == pattern.hash()
+
+    companion object {
+        /**
+         *
+         * I chose the nearest prime number for the size of the alphabet
+         *
+         * my alphabet is [a-z] [A-Z] ! , .
+         *
+         * size of the alphabet = 26 + 26 + 3 = 55 (is not prime)
+         *
+         */
+        private const val primeCoefficient = 53
+    }
+}

src/test/kotlin/other/ParenthesisCheckTest.kt

@@ -0,0 +1,44 @@
+package other
+
+import org.junit.Test
+import org.junit.jupiter.api.Assertions
+
+internal class ParenthesisCheckTest {
+
+    private val parenthesisCheck = ParenthesisCheck()
+
+    @Test
+    fun test_default_c_program() {
+        Assertions.assertEquals(true, parenthesisCheck.check())
+    }
+
+    @Test
+    fun test_failed_c_program() {
+        val failCode = """
+            void main({
+                printf("Hello, World!";
+            }
+        """.trimIndent()
+        Assertions.assertEquals(false, parenthesisCheck.check(failCode))
+    }
+
+    @Test
+    fun test_statement_1() {
+        val statement = "(([[]])}".trimIndent()
+        Assertions.assertEquals(false, parenthesisCheck.check(statement))
+    }
+
+    @Test
+    fun test_statement_2() {
+        val statement = "(([[()]])){}{}()".trimIndent()
+        Assertions.assertEquals(true, parenthesisCheck.check(statement))
+    }
+
+    @Test
+    fun test_statement_3() {
+        val statement = "(([[()]])){}{}([)".trimIndent()
+        Assertions.assertEquals(false, parenthesisCheck.check(statement))
+    }
+
+
+}

src/test/kotlin/other/SieveOfEratosthenesTest.kt

@@ -1,16 +1,24 @@
 package other
 
 import org.junit.Test
-import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Assertions
 
 internal class SieveOfEratosthenesTest {
 
     @Test
-    fun test() {
+    fun test_success() {
         val eratosthenes = SieveOfEratosthenes()
         val actual = eratosthenes.compute(10)
         val expected = listOf(2, 3, 5, 7)
-        assertEquals(expected, actual)
+        Assertions.assertEquals(expected, actual)
+    }
+
+    @Test
+    fun test_fail() {
+        val eratosthenes = SieveOfEratosthenes()
+        val actual = eratosthenes.compute(5)
+        val expected = listOf(4)
+        Assertions.assertNotEquals(expected, actual)
     }
 
 }

src/test/kotlin/other/StringEqualsHashTest.kt

@@ -0,0 +1,26 @@
+package other
+
+import org.junit.Test
+import org.junit.jupiter.api.Assertions
+
+internal class StringEqualsHashTest {
+
+    private val stringEqualsHash = StringEqualsHash()
+
+    @Test
+    fun test_two_the_same_strings() {
+        val str1 = "Twilight Sparkle"
+        val str2 = "Twilight Sparkle"
+
+        Assertions.assertEquals(true, stringEqualsHash.equals(str1, str2))
+    }
+
+    @Test
+    fun test_two_different_strings() {
+        val greeting = "How are you?"
+        val pattern = "Happy birthday to me!"
+
+        Assertions.assertEquals(false, stringEqualsHash.equals(greeting, pattern))
+    }
+
+}