Create 0895-maximum-frequency-stack.kt

Author: a93a

kotlin/0895-maximum-frequency-stack.kt

@@ -0,0 +1,31 @@
+class FreqStack() {
+
+    val countMap = HashMap<Int, Int>()
+    var max = 0
+    val stackMap = HashMap<Int, ArrayDeque<Int>>()
+
+    fun push(`val`: Int) {
+        val count = countMap.getOrDefault(`val`, 0) + 1
+        countMap[`val`] = count
+        if (count > max) {
+            max = count
+            stackMap.put(max, ArrayDeque())
+        }
+        stackMap[count]!!.addFirst(`val`)
+    }
+
+    fun pop(): Int {
+        val res = stackMap[max]!!.removeFirst()
+        countMap[res] = countMap[res]!! - 1
+        if(stackMap[max]!!.isEmpty()) max--
+        return res
+    }
+
+}
+
+/**
+ * Your FreqStack object will be instantiated and called as such:
+ * var obj = FreqStack()
+ * obj.push(`val`)
+ * var param_2 = obj.pop()
+ */