Finished exercise 7

src/main/kotlin/exercise2/task1/FindPairOfHighestSum.kt

@@ -18,7 +18,10 @@ import org.jetbrains.exercise2.task3.findPairWithBiggestDifference
  */
 
 internal fun List<Int>.findHighestSumPair(): Pair<Int, Int> {
-    TODO("Implement me!!")
+    val prvi = this.sorted().get(this.lastIndex)
+    val drugi = this.sorted().get(this.lastIndex-1)
+
+    return Pair(prvi, drugi)
 }
 
 fun main() {

src/main/kotlin/exercise2/task2/FindPairOfHighestSumFunctional.kt

@@ -20,7 +20,9 @@ import org.jetbrains.exercise2.task3.findPairWithBiggestDifference
  */
 
 internal fun List<Int>.findHighestSumPairFunctional(): Pair<Int, Int> {
-    TODO("Implement me!!")
+    return Pair(
+        this.sorted().get(this.lastIndex), this.sorted().get(this.lastIndex-1)
+    )
 }
 
 fun main() {

src/main/kotlin/exercise2/task3/ConvertMethodToFunctionalApproach.kt

@@ -17,24 +17,29 @@ import kotlin.math.abs
  */
 
 internal fun List<Int>.findPairWithBiggestDifference(): Pair<Int, Int> {
-    // TODO refactor me to functional approach and make tests pass!!!
-    var resultPair: Pair<Int, Int>? = null
-    var biggestDifference = Int.MIN_VALUE
-
-    for (i in this.indices) {
-        for (j in (i + 1) until this.size) {
-            val first = this[i]
-            val second = this[j]
-            val absDifference = abs(first - second)
-
-            if (absDifference >= biggestDifference) {
-                biggestDifference = absDifference
-                resultPair = Pair(first, second)
-            }
-        }
-    }
 
-    return resultPair!!
+    return Pair(
+        this.sorted().get(this.size-1), this.sorted().get(0)
+    )
+
+
+//    var resultPair: Pair<Int, Int>? = null
+//    var biggestDifference = Int.MIN_VALUE
+//
+//    for (i in this.indices) {
+//        for (j in (i + 1) until this.size) {
+//            val first = this[i]
+//            val second = this[j]
+//            val absDifference = abs(first - second)
+//
+//            if (absDifference >= biggestDifference) {
+//                biggestDifference = absDifference
+//                resultPair = Pair(first, second)
+//            }
+//        }
+//    }
+//
+//    return resultPair!!
 }
 
 fun main() {

src/main/kotlin/exercise2/task4/ProcessCountriesData.kt

@@ -59,27 +59,31 @@ internal val countries = listOf(
  */
 
 internal fun List<Country>.findCountryWithBiggestTotalArea(): Country {
-    TODO("Implement me!!!")
+    return countries.maxBy { it.totalAreaInSquareKilometers }
 }
 
 internal fun List<Country>.findCountryWithBiggestPopulation(): Country {
-    TODO("Implement me!!!")
+   return countries.maxBy { it.population }
 }
 
 internal fun List<Country>.findCountryWithHighestPopulationDensity(): Country {
-    TODO("Implement me!!!")
+    return countries.maxBy { it.population/it.totalAreaInSquareKilometers }
 }
 
 internal fun List<Country>.findCountryWithLowestPopulationDensity(): Country {
-    TODO("Implement me!!!")
+    return countries.minBy { it.population/it.totalAreaInSquareKilometers }
 }
 
 internal fun List<Country>.findLanguageSpokenInMostCountries(): String {
-    TODO("Implement me!!!")
+    return countries.flatMap { it.languages }
+        .groupingBy { it }
+        .eachCount()
+        .maxBy { it.value }
+        .key
 }
 
 internal fun List<Country>.filterCountriesThatSpeakLanguage(language: String): List<Country> {
-    TODO("Implement me!!!")
+    return countries.filter { country -> country.languages.contains(language) }
 }
 
 
@@ -88,7 +92,7 @@ fun main() {
     println("Country with a biggest population is a ${countries.findCountryWithBiggestPopulation().name}")
     println("Country with a biggest population density is a ${countries.findCountryWithHighestPopulationDensity().name}")
     println("Country with a lowest population density is a ${countries.findCountryWithLowestPopulationDensity().name}")
-    println("Language spoken in most countries is a ${countries.findLanguageSpokenInMostCountries()}")
+    println("Language spoken in most countries is ${countries.findLanguageSpokenInMostCountries()}")
     val countriesThatSpeakEnglish = countries.filterCountriesThatSpeakLanguage("English")
     println("Countries that speak English language are ${countriesThatSpeakEnglish.joinToString { it.name }}")
 }

src/main/kotlin/exercise2/task5/CreateUserDSL.kt

@@ -49,11 +49,15 @@ internal data class Address(
  */
 
 internal fun user(initUser: User.() -> Unit): User {
-    TODO("Implement me!!!")
+    val user = User()
+    return user.apply(initUser)
 }
 
-internal fun User.address(initAddress: Address.() -> Unit): User {
-    TODO("Implement me!!!")
+internal fun User.address   (initAddress: Address.() -> Unit): User {
+    val adr = Address()
+    adr.initAddress()
+    this.address = adr
+    return this
 }
 
 fun main() {