Merge pull request #3596 from drxlx/0981-time-based-key-value-store

Create 0981-time-based-key-value-store.swift

Author: aifedorov

Diff for: swift/0981-time-based-key-value-store.swift

@@ -0,0 +1,37 @@
+
+class TimeMap {
+    var store = [String: [(String, Int)]]()
+    init() {
+        
+    }
+    
+    func set(_ key: String, _ value: String, _ timestamp: Int) {
+        store[key, default: []].append((value, timestamp))
+    }
+    
+    func get(_ key: String, _ timestamp: Int) -> String {
+        var res = ""
+        var values = store[key] ?? []
+
+        var l = 0
+        var r = values.count - 1
+        while l <= r {
+            let m = l + ((r - l) / 2)
+            if values[m].1 <= timestamp { 
+                res = values[m].0
+                l = m + 1
+            } else {
+                r = m - 1
+            }
+        }
+
+        return res
+    }
+}
+
+/**
+ * Your TimeMap object will be instantiated and called as such:
+ * let obj = TimeMap()
+ * obj.set(key, value, timestamp)
+ * let ret_2: String = obj.get(key, timestamp)
+ */