Finished excercises 1 and 2 (Aleksa Martinović) #3

LX002 · 2024-03-21T21:27:09Z

Rešeni zadaci sa prvih i drugih praktičnih vežbi i kreiranje pull request-a.

vuksa · 2024-03-26T09:30:04Z

src/main/kotlin/exercise1/task1/GradeCalculator.kt

@@ -40,13 +40,25 @@ import java.util.Scanner
 */

 internal fun calculateGrade(score: Int): Int {
-    TODO("Implement me!!!")
+//    require(score in 0..100) {


nit: Please remove the commented-out code before pushing the changes.

vuksa · 2024-03-26T09:30:57Z

src/main/kotlin/exercise1/task3/ScrabbleWordScoreCalculator.kt

 internal fun calculateWordScrabbleScore(word: String): Int {
-    TODO("Implement me!!!")
+    return word.sumOf { charMap.getOrDefault(it.uppercaseChar(), 0) }


Very nice usage of Map#getOrDefault function. Great job!

vuksa · 2024-03-26T09:33:42Z

src/main/kotlin/exercise1/task5/ReverseInteger.kt

@@ -27,10 +29,10 @@ package org.jetbrains.exercise1.task5
 */

 internal fun reverseInteger(x: Int): Int {
-    TODO("Implement me!!!")
+    require(x in -1000000..1000000) { "Number must be integer in range -1000000..1000000" }
+    return if (x < 0) ("-" + abs(x).toString().reversed()).toInt() else x.toString().reversed().toInt()


In this particular case,
abs(x).toString().reversed()).toInt() and x.toString().reversed().toInt() expressions always provide the same result, so it's a safe to store a abs(x).toString().reversed()).toInt() value to a variable and only prefix the - sign in case number is negative.

vuksa · 2024-03-26T09:35:10Z

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

+    require(this.all { it in -1000..1000 })
+    var maxSum = Integer.MIN_VALUE
+    var pair: Pair<Int, Int>? = null
+    for((index, item) in this.dropLast(1).withIndex()) {


Well-used withIndex extension function. Good job!

vuksa · 2024-03-26T09:37:02Z

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

-    }
-
-    return resultPair!!
+//    STANDARD WAY:


nit: Same thing a in the first task, please keep your code clean and do not push commented out code :)

vuksa · 2024-03-26T09:41:59Z

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

+        .map{ it -> it.first }
+        .first()


Here, we can apply a small optimization and avoid unnecessary map calls that operate over the entire collection. Since we are only interested in the single language that is used in most countries, instead of map { ... }.first() call, we can do the following:

Suggested change

.map{ it -> it.first }

.first()

.first()

.first

Also please note that first() function call will throw an exception if the receiver list object is empty.

vuksa · 2024-03-26T09:43:29Z

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

 }

 internal fun List<Country>.findLanguageSpokenInMostCountries(): String {
-    TODO("Implement me!!!")
+    return this.flatMap { it.languages }


Good job! 👏🏻

vuksa · 2024-03-26T09:44:15Z

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

@@ -49,11 +49,16 @@ internal data class Address(
 */

 internal fun user(initUser: User.() -> Unit): User {
-    TODO("Implement me!!!")
+    val user = User()


That is it! We can also write this with the scoped functions:

Suggested change

val user = User()

return User().apply(initUser)

vuksa · 2024-03-26T09:45:12Z

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

 }

 internal fun User.address(initAddress: Address.() -> Unit): User {
-    TODO("Implement me!!!")
+    val address = Address()


Same as in an exemple above, we can use scoped functions.

Suggested change

val address = Address()

return apply { address = Address().apply(initAddress) }

vuksa · 2024-03-26T09:48:10Z

Well done, it seems your feeling for the Kotlin programming approach really starts to kick in!
Please pay attention to cleaning up the code from any commented-out code blocks before you push the changes.

vuksa · 2024-04-06T13:37:02Z

src/main/kotlin/exercise3/task1/BalancedBrackets.kt

+
+    for(char in expression) {
+        when(char) {
+            in openBrackets -> brackets.add(char)


The solution is correct. Readability can be improved by using the map as a data structure.

vuksa · 2024-04-06T13:37:46Z

src/main/kotlin/exercise3/task2/ParenthesesClusters.kt

 }

 fun main() {
    val expressionsToClustersCatalog = mapOf(
+        "()(" to listOf("()"),


This actually should return the empty list since one cluster isn't closed.

vuksa · 2024-04-06T13:46:20Z

src/main/kotlin/exercise3/task3/SherlockValidatesString.kt

+    return when {
+        cMin == cMax -> "YES"
+        cMax - cMin == 1 && occurrences.count { it == cMax } == 1 -> "YES"
+        cMin == 1 && occurrences.count { it == cMin } == 1 && occurrences.count { it == cMax } == occurrences.size - 1 -> "YES"


If I'm not mistaken, your solution isn't fully correct.
for the test case as, your function would return YES even though the expected result should be NO.

vuksa · 2024-04-06T13:48:16Z

src/main/kotlin/exercise3/task4/TaxiParkTask.kt

 }

 /**
 * Subtask 2:
 * Find all the clients who completed at least the given number of trips.
 */
 internal fun TaxiPark.findFaithfulPassengers(minTrips: Int): Set<Passenger> {
-    TODO("Implement me!!!")
+    //test ovde ne prolazi, nisam siguran zasto
+    return this.trips


The solution seems correct; the issue was in the test I pushed afterward.
Please sync with the latest main branch state.

vuksa · 2024-04-06T13:49:13Z

src/main/kotlin/exercise3/task4/TaxiParkTask.kt

+        .map { it.passengers }
+        .forEach {
+            it.forEach {
+                allPassengers.add(it)
+            }
+        }


Instead of this you can simply use flatmap which will convert list of lists to list.

vuksa · 2024-04-06T13:49:30Z

src/main/kotlin/exercise3/task4/TaxiParkTask.kt

+    return passengersMap.filterValues { discounts ->
+            val withDiscount = discounts.count { it }
+            val noDiscount = discounts.size - withDiscount
+            withDiscount > noDiscount


Well done! :)

Finished excercises 1 and 2 (Aleksa Martinovic)

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vuksa reviewed Mar 26, 2024

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vuksa force-pushed the main branch 2 times, most recently from 9db668d to 189c667 Compare March 27, 2024 16:39

vuksa added exercise1 exercise2 labels Mar 28, 2024

LX002 and others added 3 commits March 30, 2024 11:12

Merge branch 'vuksa:main' into main

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Rešeni zadaci sa 3. vežbi

7cc984e

Ispravljene vežbe 1 i 2

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LX002 closed this Mar 30, 2024

LX002 reopened this Mar 30, 2024

vuksa added the exercise3 label Apr 6, 2024

vuksa reviewed Apr 6, 2024

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vuksa added the reviewed label Apr 20, 2024

vuksa force-pushed the main branch from 88b1e45 to 7cb5058 Compare April 29, 2024 10:58

vuksa force-pushed the main branch from 1d65b39 to b503e6b Compare May 20, 2024 10:38

vuksa force-pushed the main branch 2 times, most recently from 6106c56 to 8296ece Compare May 20, 2024 11:17

	val address = Address()
	return apply { address = Address().apply(initAddress) }

Finished excercises 1 and 2 (Aleksa Martinović) #3

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Finished excercises 1 and 2 (Aleksa Martinović) #3

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LX002 commented Mar 21, 2024

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vuksa commented Mar 26, 2024

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vuksa Apr 6, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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vuksa Apr 6, 2024 •

edited

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