Merge pull request #275 from wellFoundedDevelopers/byeonghee/65week

[소병희] - 사과나무, 후위 표기식

src/main/kotlin/byeonghee/week65/사과나무.kt

@@ -0,0 +1,29 @@
+package byeonghee.week65
+
+class 소병희_사과나무 {
+    companion object {
+        fun solve() = with(System.`in`.bufferedReader()) {
+            val n = readLine().toInt()
+            val trees = IntArray(n)
+
+            var oneCnt = 0 //1 짜리 물뿌리개의 최소 필요개수
+            var twoCnt = 0 // 2짜리 물뿌리개의 최대 필요개수
+            var sum = 0
+
+            readLine().split(" ").forEachIndexed { i, v ->
+                trees[i] = v.toInt().also {
+                    if (it % 2 == 1) oneCnt++
+                    if (it >= 2) twoCnt += it / 2
+                    sum += it
+                }
+            }
+
+            if (sum % 3 > 0 || oneCnt > twoCnt) println("NO")
+            else println("YES")
+        }
+    }
+}
+
+fun main() {
+    소병희_사과나무.solve()
+}

src/main/kotlin/byeonghee/week65/후위 표기식.kt

@@ -0,0 +1,46 @@
+package byeonghee.week65
+
+class 소병희_후위표기식 {
+    companion object {
+        val op = charArrayOf('+', '-', '*', '/', '(', ')')
+
+        fun solve() = with(System.`in`.bufferedReader()) {
+            val st = ArrayDeque<Char>()
+            val sb = StringBuilder()
+            val pri = HashMap<Char, Int>()
+            pri.put('+', 1)
+            pri.put('-', 1)
+            pri.put('*', 2)
+            pri.put('/', 2)
+            pri.put('(', 0)
+            pri.put(')', 0)
+
+            readLine().forEach { i ->
+                if (i !in op) sb.append(i)
+                else if (i == '(') st.add(i)
+                else if (i == ')') {
+                    while (st.isNotEmpty() && st.last() != '(') {
+                        sb.append(st.removeLast())
+                    }
+                    if (st.isNotEmpty()) st.removeLast()
+                }
+                else {
+                    while(st.isNotEmpty() && pri[st.last()]!! >= pri[i]!!) {
+                        sb.append(st.removeLast())
+                    }
+                    st.add(i)
+                }
+            }
+
+            while(st.isNotEmpty()) {
+                sb.append(st.removeLast())
+            }
+
+            println(sb)
+        }
+    }
+}
+
+fun main() {
+    소병희_후위표기식.solve()
+}