05 & 06 exercises (#114)

Co-authored-by: Aditya Bhargava <bluemangroupie@gmail.com>

05_hash_tables/kotlin/01_price_of_groceries.kt

@@ -1,3 +1,4 @@
+
 fun main(args: Array<String>)  {
 
     val book = hashMapOf<String, Double>(
@@ -7,4 +8,4 @@ fun main(args: Array<String>)  {
     )
 
     println(book)
-}
+}

05_hash_tables/kotlin/02_check_voter.kt

@@ -16,4 +16,4 @@ fun main(args: Array<String>) {
     checkVoter("tom")
     checkVoter("mike")
     checkVoter("mike")
-}
+}

06_breadth-first_search/kotlin/01_breadth-first_search.kt

@@ -0,0 +1,29 @@
+import java.util.*
+
+val graph = hashMapOf(
+	"You" to listOf("Sergey", "Viktoria"),
+	"Viktoria" to listOf("Sergey", "Vladimir"),
+	"Vladimir" to listOf("Sergey", "Andrew", "Nikita", "Boris")
+)
+
+private fun breadthFirstSearch(name: String) {
+	val queue = ArrayDeque(graph[name])
+	val searched = arrayListOf<String>()
+	while (queue.isNotEmpty()) {
+		val person = queue.poll()
+		if (!searched.contains(person)) {
+			if (personIsSeller(person)) {
+				println("$person is a mango seller!")
+				return
+			} else {
+				graph[person]?.let { queue.addAll(it) }
+				searched.add(person)
+			}
+		}
+	}
+	println("No mango sellers found!")
+}
+
+private fun personIsSeller(name: String): Boolean = name.endsWith("s")
+
+fun main(args: Array<String>) = println(breadthFirstSearch("You"))

06_breadth-first_search/kotlin/BreadthFirstSearch.kt

@@ -1,50 +0,0 @@
-typealias Graph<V> = MutableMap<V, List<V>>
-
-fun <V> Graph<V>.breadthFirstSearch(key: V, isSearched: (V) -> Boolean): Boolean {
-    val queue: Deque<V> = LinkedList()
-    this[key]?.let { queue += it }
-    val searched = HashSet<V>()
-    while (queue.isNotEmpty()) {
-        val value = queue.pop()
-        if (!searched.contains(value))
-            if (isSearched(value)) {
-                println("value $value is here!")
-                return true
-            } else {
-                this[value]?.let { queue += it }
-                searched.add(value)
-            }
-    }
-    return false
-}
-
-data class Person(
-        val name: String,
-        val isSellerMango: Boolean = false
-) {
-    override fun equals(other: Any?): Boolean =
-            if (other is Person) other.name == name
-            else false
-
-
-    override fun hashCode(): Int {
-        return name.length
-    }
-}
-
-fun main(args: Array<String>) {
-
-    val graph: Graph<Person> = HashMap()
-
-    (graph as java.util.HashMap<Person, List<Person>>).apply {
-        put(Person("John"), listOf(Person("Sergey"), Person("Viktoria")))
-        put(Person("Viktoria"), listOf(Person("Sergey"), Person("Phara")))
-        put(Person("Phara"), listOf(Person("Sergey"), Person("Thrall"), Person("Xul"), Person("Juncart", true)))
-    }
-
-    println(
-            graph.breadthFirstSearch(Person("John"), Person::isSellerMango)
-    )
-
-
-}