Swift implementation for LCOF 41

Author: klever34

lcof/面试题41. 数据流中的中位数/README.md

@@ -412,6 +412,44 @@ public class MedianFinder {
  */
 ```
 
+#### Swift
+
+```swift
+class MedianFinder {
+    private var lowerHalf = [Int]()
+    private var upperHalf = [Int]()
+
+    init() {}
+
+    func addNum(_ num: Int) {
+        if lowerHalf.count > upperHalf.count {
+            lowerHalf.append(num)
+            lowerHalf.sort(by: >)
+            upperHalf.append(lowerHalf.removeFirst())
+        } else {
+            upperHalf.append(num)
+            upperHalf.sort()
+            lowerHalf.append(upperHalf.removeFirst())
+        }
+    }
+
+    func findMedian() -> Double {
+        if lowerHalf.count > upperHalf.count {
+            return Double(lowerHalf.first!)
+        } else {
+            return (Double(lowerHalf.first!) + Double(upperHalf.first!)) / 2.0
+        }
+    }
+}
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * let obj = MedianFinder();
+ * obj.addNum(num);
+ * let param_2 = obj.findMedian();
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof/面试题41. 数据流中的中位数/Solution.swift

@@ -0,0 +1,33 @@
+class MedianFinder {
+    private var lowerHalf = [Int]()
+    private var upperHalf = [Int]()
+
+    init() {}
+
+    func addNum(_ num: Int) {
+        if lowerHalf.count > upperHalf.count {
+            lowerHalf.append(num)
+            lowerHalf.sort(by: >)
+            upperHalf.append(lowerHalf.removeFirst())
+        } else {
+            upperHalf.append(num)
+            upperHalf.sort()
+            lowerHalf.append(upperHalf.removeFirst())
+        }
+    }
+
+    func findMedian() -> Double {
+        if lowerHalf.count > upperHalf.count {
+            return Double(lowerHalf.first!)
+        } else {
+            return (Double(lowerHalf.first!) + Double(upperHalf.first!)) / 2.0
+        }
+    }
+}
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * let obj = MedianFinder();
+ * obj.addNum(num);
+ * let param_2 = obj.findMedian();
+ */