solve

Author: sonjh1217

contains-duplicate/sonjh1217.swift

@@ -0,0 +1,14 @@
+class Solution {
+    // time O(n) / space O(n)
+    func containsDuplicate(_ nums: [Int]) -> Bool {
+        var numSet = Set<Int>()
+        for num in nums {
+            if numSet.contains(num) {
+                return true
+            }
+            numSet.insert(num)
+        }
+
+        return false
+    }
+}