refactor : dongho님 review 반영

Author: ChanwooAn

src/4week/acw/근손실.kt

@@ -8,10 +8,7 @@ class `acw근손실` {
 
     fun makePermutation(arr: MutableList<Int>, power: Int, day: Int, N: Int, K: Int) {
         //순열구성하기
-        var powerNow = power
-        if (arr.isNotEmpty()) {
-            powerNow = power + arr.last() - K
-        }
+        val powerNow = power + (arr.takeIf { it.isNotEmpty() }?.let { it.last() - K } ?: 0)
 
         if (powerNow < 500) {
             return
@@ -50,5 +47,4 @@ class `acw근손실` {
 fun main() {
     val sol = `acw근손실`()
     sol.solution()
-}
-
+}

src/4week/acw/주차요금계산.kt

@@ -5,34 +5,48 @@ class Solution {
     val recordsArr = Array(10000) { LinkedList<String>() }
     val feeArr = Array(10000) { 0 }
 
+    data class Time(var hour: Int, var min: Int) {
+
+        constructor(hourAndMin: List<Int>) : this(hourAndMin[0], hourAndMin[1]) {
+            this.hour = hourAndMin[0]
+            this.min = hourAndMin[1]
+        }
+
+        companion object {
+            fun calcUsingTime(inTime: Time, outTime: Time): Int {
+                return (outTime.hour * 60 + outTime.min - inTime.hour * 60 - inTime.min)
+            }
+        }
+    }
+
+    fun String.timeSplit() = split(":").map { it.toInt() }
+
     fun solution(fees: IntArray, records: Array<String>): IntArray {
         var answer: IntArray = intArrayOf()
+
         for (i in records) {
             val (time, num, inout) = i.split(" ")
             if (inout == "IN") {
                 recordsArr[num.toInt()].add(time)
             } else {
                 //out이 나올경우에는 바로 해당번호에 대해 처리를 해준다.
-                val inTime = recordsArr[num.toInt()].removeLast()
+                val inTime = Time((recordsArr[num.toInt()].removeLast().timeSplit()))
+                val outTime = Time(time.timeSplit())
 
-                val inHM = inTime.split(":").map { it.toInt() }
-                val outHM = time.split(":").map { it.toInt() }
-
-                val usingTime = outHM[0] * 60 + outHM[1] - inHM[0] * 60 - inHM[1]
+                val usingTime = Time.calcUsingTime(inTime, outTime)
                 feeArr[num.toInt()] += usingTime
             }
         }
 
         for (i in 0 until 10000) {
             while (recordsArr[i].isNotEmpty()) {
-                val now = recordsArr[i].removeFirst().split(":").map { it.toInt() }
-                val usingTime = 23 * 60 + 59 - now[0] * 60 - now[1]
+                val now = Time(recordsArr[i].removeFirst().timeSplit())
+                val usingTime = Time.calcUsingTime(Time(23, 59), now)
                 feeArr[i] += usingTime
             }
         }//In은 했는데 Out은 안한경우 위에서 처리가 안되므로 처음부터 돌면서 23:59에서 빼준다.
 
 
-
         //요금 계산하기
         val arr = mutableListOf<Int>()
         for (i in 0 until 10000) {

src/4week/acw/톱니바퀴.kt

@@ -14,16 +14,15 @@ class `acw톱니바퀴` {
     var turn = arrayListOf<Pair<Int, Int>>()
 
 
-    fun addTurn(w: Int, turnD: Int) {
+    private fun addTurn(w: Int, turnD: Int) {
         //dfs로 들어가면서 회전해야할 것들 turn에 추가해주기
 
 
-        var wheelNowRight = if (wheel[w] and (1 shl RIGHT) != 0) 1 else 0
-        var wheelNowLeft = if (wheel[w] and (1 shl LEFT) != 0) 1 else 0
+        val wheelNowRight = if (wheel[w] and (1 shl RIGHT) != 0) 1 else 0
+        val wheelNowLeft = if (wheel[w] and (1 shl LEFT) != 0) 1 else 0
 
         if (w - 1 >= 0) {
             val leftWheelsRight = if (wheel[w - 1] and (1 shl RIGHT) != 0) 1 else 0
-
             if (wheelNowLeft != leftWheelsRight && !visit[w - 1]) {
                 visit[w - 1] = true
                 turn.add(Pair(w - 1, turnD * -1))
@@ -43,7 +42,7 @@ class `acw톱니바퀴` {
 
     }
 
-    fun turnWheel() {
+    private fun turnWheel() {
 
         while (turn.isNotEmpty()) {
             val (w, d) = turn.removeFirst()
@@ -100,10 +99,11 @@ class `acw톱니바퀴` {
         }
 
 
-        var answer = 0
-        for (i in 0 until 4) {
-            if ((wheel[i] and (1 shl 7)) != 0) {
-                answer += (2.0).pow(i).toInt()
+        val answer = wheel.withIndex().sumOf { (idx, value) ->
+            if (value and (1 shl 7) != 0) {
+                (2.0).pow(idx).toInt()
+            } else {
+                0
             }
         }
 

src/4week/acw/트리의부모찾기.kt

@@ -1,7 +1,7 @@
 package `4week`.acw
 
 class `acw트리의부모찾기` {
-    lateinit var treeMap: Array<MutableList<Int>>
+    lateinit var treeMap: Array<MutableSet<Int>>
     lateinit var parent: Array<Int>
     var N = 0
 
@@ -18,7 +18,7 @@ class `acw트리의부모찾기` {
 
     fun solution() {
         N = readln().toInt()
-        treeMap = Array(N + 1) { mutableListOf() }
+        treeMap = Array(N + 1) { mutableSetOf() }
         parent = Array(N + 1) { 0 }
 
         for (i in 1 until N) {
@@ -29,9 +29,7 @@ class `acw트리의부모찾기` {
         }
 
         dfs(1)
-        for (i in 2..N) {
-            println(parent[i])
-        }
+        println(parent.drop(2).joinToString("\n"))
 
     }
 }

src/4week/acw/회의실배정.kt

@@ -1,26 +1,19 @@
 package `4week`.acw
 
-
 import java.util.PriorityQueue
 
-class `acw회의실배정` {
-    val conferance = PriorityQueue<Pair<Int, Int>>(
-        Comparator { a, b ->
-            if (a.second - b.second == 0) {
-                a.first - b.first
-            } else {
-                a.second - b.second
-            }
-        }
 
+class `acw회의실배정` {
+    val conferance = PriorityQueue(
+        compareBy<Pair<Int, Int>> {it.second}.thenBy { it.first }
     )
 // 종료시간이 빠른것을 기준으로 정렬한다.
 // 종료시간이 같을 경우 시작시간이 더 빠른것을 위주로 정렬해야한다. -> 시작시간과 종료시간이 같은 회의가 있을 수 있기 때문
 // ex) 5,6 / 6,6 이 있는데 6,6이 먼저 뽑힐 경우 56 /66이 모두 사용될 수 있음에도 불구하고 56은 선택되지 못한다.
 
     fun solution() {
         val N = readln().toInt()
-        var answer = 0
+        var answer = 1
         var lastConferance = Pair(0, 0)
 
         repeat(N) {
@@ -29,14 +22,11 @@ class `acw회의실배정` {
 
         }
         lastConferance = conferance.poll()
-        answer++
 
 
         while (conferance.isNotEmpty()) {
             val nowConferance = conferance.poll()
-            if (nowConferance.first < lastConferance.second) {
-                continue
-            } else {
+            if (nowConferance.first >= lastConferance.second) {
                 lastConferance = nowConferance
                 answer++
             }
@@ -53,3 +43,4 @@ fun main() {
     val sol = `acw회의실배정`()
     sol.solution()
 }
+