Data commit

Task/Longest-increasing-subsequence/Swift/longest-increasing-subsequence.swift

@@ -0,0 +1,48 @@
+import Foundation
+
+extension Array where Element: Comparable {
+  @inlinable
+  public func longestIncreasingSubsequence() -> [Element] {
+    var startI = [Int](repeating: 0, count: count)
+    var endI = [Int](repeating: 0, count: count + 1)
+    var len = 0
+
+    for i in 0..<count {
+      var lo = 1
+      var hi = len
+
+      while lo <= hi {
+        let mid = Int(ceil((Double(lo + hi)) / 2))
+
+        if self[endI[mid]] <= self[i] {
+          lo = mid + 1
+        } else {
+          hi = mid - 1
+        }
+      }
+
+      startI[i] = endI[lo-1]
+      endI[lo] = i
+
+      if lo > len {
+        len = lo
+      }
+    }
+
+    var s = [Element]()
+    var k = endI[len]
+
+    for _ in 0..<len {
+      s.append(self[k])
+      k = startI[k]
+    }
+
+    return s.reversed()
+  }
+}
+
+let l1 = [3, 2, 6, 4, 5, 1]
+let l2 = [0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15]
+
+print("\(l1) = \(l1.longestIncreasingSubsequence())")
+print("\(l2) = \(l2.longestIncreasingSubsequence())")