start ocm-typed

quad/ocm-typed.rkt

@@ -0,0 +1,35 @@
+#lang typed/racket/base
+(require (for-syntax racket/base racket/syntax))
+(require racket/list sugar/debug rackunit racket/function racket/vector sugar/cache "logger-typed.rkt")
+(define-logger ocm)
+
+#|
+Totally monotone matrix searching algorithms.
+
+The offline algorithm in ConcaveMinima is from Agarwal, Klawe, Moran,
+Shor, and Wilbur, Geometric applications of a matrix searching algorithm,
+Algorithmica 2, pp. 195-208 (1987).
+
+The online algorithm in OnlineConcaveMinima is from Galil and Park,
+A linear time algorithm for concave one-dimensional dynamic programming,
+manuscript, 1989, which simplifies earlier work on the same problem
+by Wilbur (J. Algorithms 1988) and Eppstein (J. Algorithms 1990).
+
+D. Eppstein, March 2002, significantly revised August 2005
+
+|#
+
+;(provide smawky? make-ocm reduce reduce2 (prefix-out ocm- (combine-out min-value min-index)))
+
+(define (select-elements xs is)
+  (map (curry list-ref xs) is))
+
+(define (odd-elements xs)
+  (select-elements xs (range 1 (length xs) 2)))
+
+(define (vector-odd-elements xs)
+  (for/vector ([i (in-range (vector-length xs))] #:when (odd? i))
+    (vector-ref xs i)))
+
+(define (even-elements xs)
+  (select-elements xs (range 0 (length xs) 2)))