top k frequent elements solution

Author: radiantchoi

top-k-frequent-elements/radiantchoi.swift

@@ -0,0 +1,17 @@
+class Solution {
+    func topKFrequent(_ nums: [Int], _ k: Int) -> [Int] {
+        var occurences = [Int: Int]()
+
+        for num in nums {
+            if let occurence = occurences[num] {
+                occurences[num] = occurence + 1
+            } else {
+                occurences[num] = 1
+            }
+        }
+
+        let numbers = occurences.keys.sorted { occurences[$0] ?? 0 > occurences[$1] ?? 0 }
+
+        return Array(numbers[0..<k])
+    }
+}