(in-package :cl-user) (eval-when (:compile-toplevel :load-toplevel :execute) (sb-int:defconstant-eqx opt #+swank '(optimize (speed 3) (safety 2)) #-swank '(optimize (speed 3) (safety 0) (debug 0)) #'equal) #+swank (ql:quickload '(:cl-debug-print :fiveam) :silent t) #-swank (set-dispatch-macro-character #\# #\> (lambda (s c p) (declare (ignore c p)) `(values ,(read s nil nil t))))) #+swank (cl-syntax:use-syntax cl-debug-print:debug-print-syntax) (defmacro define-int-types (&rest bits) `(progn ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "UINT~A" b)) () '(unsigned-byte ,b))) bits) ,@(mapcar (lambda (b) `(deftype ,(intern (format nil "INT~A" b)) () '(signed-byte ,b))) bits))) (define-int-types 2 4 7 8 15 16 31 32 62 63 64) (defconstant +mod+ 1000000007) (defmacro dbg (&rest forms) #+swank (if (= (length forms) 1) `(format *error-output* "~A => ~A~%" ',(car forms) ,(car forms)) `(format *error-output* "~A => ~A~%" ',forms `(,,@forms))) #-swank (declare (ignore forms))) (declaim (inline println)) (defun println (obj &optional (stream *standard-output*)) (let ((*read-default-float-format* 'double-float)) (prog1 (princ obj stream) (terpri stream)))) ;; BEGIN_INSERTED_CONTENTS (defpackage :cp/read-fixnum (:use :cl) (:export #:read-fixnum)) (in-package :cp/read-fixnum) (declaim (ftype (function * (values fixnum &optional)) read-fixnum)) (defun read-fixnum (&optional (in *standard-input*)) "NOTE: cannot read -2^62" (declare #.cl-user::opt) (macrolet ((%read-byte () `(the (unsigned-byte 8) #+swank (char-code (read-char in nil #\Nul)) #-swank (sb-impl::ansi-stream-read-byte in nil #.(char-code #\Nul) nil)))) (let* ((minus nil) (result (loop (let ((byte (%read-byte))) (cond ((<= 48 byte 57) (return (- byte 48))) ((zerop byte) ; #\Nul (error "Read EOF or #\Nul.")) ((= byte #.(char-code #\-)) (setq minus t))))))) (declare ((integer 0 #.most-positive-fixnum) result)) (loop (let* ((byte (%read-byte))) (if (<= 48 byte 57) (setq result (+ (- byte 48) (* 10 (the (integer 0 #.(floor most-positive-fixnum 10)) result)))) (return (if minus (- result) result)))))))) (defpackage :cp/inverse-table (:use :cl) (:export #:make-inverse-table #:make-monotone-inverse-table!)) (in-package :cp/inverse-table) (declaim (inline make-reverse-inverse-table)) (defun make-inverse-table (vector &key (test #'eql)) "Returns a hash-table that assigns each value of the (usually sorted) VECTOR of length n to the integers 0, ..., n-1." (let ((table (make-hash-table :test test :size (length vector)))) (dotimes (i (length vector) table) (setf (gethash (aref vector i) table) i)))) (declaim (inline make-monotone-inverse-table!)) (defun make-monotone-inverse-table! (vector &key (test #'eql) (order #'<)) "Sorts VECTOR, deletes all adjacent duplicates, and returns a hash-table that assigns each value of the vector to the integers 0, 1, ..." (declare (function test order) (vector vector) (inline sort)) (setq vector (sort vector order)) (let ((table (make-hash-table :test test :size (length vector))) (index 0)) (declare ((integer 0 #.most-positive-fixnum) index)) (dotimes (pos (length vector)) (when (or (zerop pos) (not (funcall test (aref vector pos) (aref vector (- pos 1))))) (setf (gethash (aref vector pos) table) index) (incf index))) (values table index))) (defpackage :cp/modify-macro (:use :cl) (:export #:minf #:maxf #:mulf #:divf #:iorf #:xorf #:andf)) (in-package :cp/modify-macro) (macrolet ((def (name fname) `(define-modify-macro ,name (new-value) ,fname))) (def minf min) (def maxf max) (def mulf *) (def divf /) (def iorf logior) (def xorf logxor) (def andf logand)) ;;; ;;; 1-dimensional binary indexed tree on arbitrary commutative monoid ;;; (defpackage :cp/abstract-bit (:use :cl) (:export #:define-bitree)) (in-package :cp/abstract-bit) (defmacro define-bitree (name &key (operator '#'+) (identity 0) sum-type (order '#'<)) "OPERATOR := binary operator (comprising a commutative monoid) IDENTITY := object (identity element of the monoid) ORDER := nil | strict comparison operator on the monoid SUM-TYPE := nil | type specifier Defines no structure; BIT is just a vector. This macro defines the three functions: -UPDATE!, point-update function, -FOLD, query function for prefix sum, and COERCE-TO-!, constructor. If ORDER is specified, this macro in addition defines -BISECT-LEFT and -BISECT-RIGHT, the bisection functions for prefix sums. (Note that these functions work only when the sequence of prefix sums (VECTOR[0], VECTOR[0]+VECTOR[1], ...) is monotone.) SUM-TYPE is used only for the type declaration: each sum VECTOR[i]+VECTOR[i+1]...+VECTOR[i+k] is declared to be this type. When SUM-TYPE is NIL, type declaration is omitted. (The array-element-type of vector itself doesn't need to be identical to SUM-TYPE.)" (let* ((name (string name)) (fname-update (intern (format nil "~A-UPDATE!" name))) (fname-fold (intern (format nil "~A-FOLD" name))) (fname-coerce (intern (format nil "COERCE-TO-~A!" name))) (fname-bisect-left (intern (format nil "~A-BISECT-LEFT" name))) (fname-bisect-right (intern (format nil "~A-BISECT-RIGHT" name)))) `(progn (declaim (inline ,fname-update)) (defun ,fname-update (bitree index delta) "Destructively increments the vector: vector[INDEX] = vector[INDEX] + DELTA" (let ((len (length bitree))) (do ((i index (logior i (+ i 1)))) ((>= i len) bitree) (declare ((integer 0 #.most-positive-fixnum) i)) (setf (aref bitree i) (funcall ,operator (aref bitree i) delta))))) (declaim (inline ,fname-fold)) (defun ,fname-fold (bitree end) "Returns the sum of the prefix: vector[0] + ... + vector[END-1]." (declare ((integer 0 #.most-positive-fixnum) end)) (let ((res ,identity)) ,@(when sum-type `((declare (type ,sum-type res)))) (do ((i (- end 1) (- (logand i (+ i 1)) 1))) ((< i 0) res) (declare ((integer -1 #.most-positive-fixnum) i)) (setf res (funcall ,operator res (aref bitree i)))))) (declaim (inline ,fname-coerce)) (defun ,fname-coerce (vector) "Destructively constructs BIT from VECTOR. (You doesn't need to call this constructor if what you need is a `zero-filled' BIT, because a vector filled with the identity element is a valid BIT as it is.)" (loop with len = (length vector) for i below len for dest-i = (logior i (+ i 1)) when (< dest-i len) do (setf (aref vector dest-i) (funcall ,operator (aref vector dest-i) (aref vector i))) finally (return vector))) ,@(when order `((declaim (inline ,fname-bisect-left)) (defun ,fname-bisect-left (bitree value) "Returns the smallest index that satisfies VECTOR[0]+ ... + VECTOR[index] >= VALUE. Returns the length of VECTOR if VECTOR[0]+ ... +VECTOR[length-1] < VALUE. Note that this function deals with a **closed** interval." (declare (vector bitree)) (if (not (funcall ,order ,identity value)) 0 (let ((len (length bitree)) (index+1 0) (cumul ,identity)) (declare ((integer 0 #.most-positive-fixnum) index+1) ,@(when sum-type `((type ,sum-type cumul)))) (do ((delta (ash 1 (- (integer-length len) 1)) (ash delta -1))) ((zerop delta) index+1) (declare ((integer 0 #.most-positive-fixnum) delta)) (let ((next-index (+ index+1 delta -1))) (when (< next-index len) (let ((next-cumul (funcall ,operator cumul (aref bitree next-index)))) ,@(when sum-type `((declare (type ,sum-type next-cumul)))) (when (funcall ,order next-cumul value) (setf cumul next-cumul) (incf index+1 delta))))))))) (declaim (inline ,fname-bisect-right)) (defun ,fname-bisect-right (bitree value) "Returns the smallest index that satisfies VECTOR[0]+ ... + VECTOR[index] > VALUE. Returns the length of VECTOR if VECTOR[0]+ ... +VECTOR[length-1] <= VALUE. Note that this function deals with a **closed** interval." (declare (vector bitree)) (if (funcall ,order value ,identity) 0 (let ((len (length bitree)) (index+1 0) (cumul ,identity)) (declare ((integer 0 #.most-positive-fixnum) index+1) ,@(when sum-type `((type ,sum-type cumul)))) (do ((delta (ash 1 (- (integer-length len) 1)) (ash delta -1))) ((zerop delta) index+1) (declare ((integer 0 #.most-positive-fixnum) delta)) (let ((next-index (+ index+1 delta -1))) (when (< next-index len) (let ((next-cumul (funcall ,operator cumul (aref bitree next-index)))) ,@(when sum-type `((declare (type ,sum-type next-cumul)))) (unless (funcall ,order value next-cumul) (setf cumul next-cumul) (incf index+1 delta)))))))))))))) #| (define-bitree bitree :operator #'+ :identity 0 :sum-type fixnum :order #'<) ;|# ; ;; Example: compute the number of inversions in a sequence #| (declaim (inline make-inverse-lookup-table)) (defun make-inverse-lookup-table (vector &key (test #'eql)) "Assigns each value of the (usually sorted) VECTOR of length n to the integers 0, ..., n-1." (let ((table (make-hash-table :test test :size (length vector)))) (dotimes (i (length vector) table) (setf (gethash (aref vector i) table) i)))) (defun count-inversions (vector &key (order #'<)) (declare (vector vector)) (let* ((len (length vector)) (inv-lookup-table (make-inverse-lookup-table (sort (copy-seq vector) order))) (bitree (make-array len :element-type '(integer 0 #.most-positive-fixnum))) (inversion-number 0)) (declare (integer inversion-number)) (loop for j below len for element = (aref vector j) for compressed = (gethash element inv-lookup-table) for delta of-type integer = (- j (bitree-fold bitree (1+ compressed))) do (incf inversion-number delta) (bitree-update! bitree compressed 1)) inversion-number)) (progn (assert (= 3 (count-inversions #(2 4 1 3 5)))) (assert (zerop (count-inversions #(0)))) (assert (zerop (count-inversions #()))) (assert (zerop (count-inversions #(1 2)))) (assert (= 1 (count-inversions #(2 1))))) ;|# ;; BEGIN_USE_PACKAGE (eval-when (:compile-toplevel :load-toplevel :execute) (use-package :cp/abstract-bit :cl-user)) (eval-when (:compile-toplevel :load-toplevel :execute) (use-package :cp/modify-macro :cl-user)) (eval-when (:compile-toplevel :load-toplevel :execute) (use-package :cp/inverse-table :cl-user)) (eval-when (:compile-toplevel :load-toplevel :execute) (use-package :cp/read-fixnum :cl-user)) (in-package :cl-user) ;;; ;;; Body ;;; (define-bitree bitree :operator #'max :identity 0 :sum-type fixnum) (declaim (ftype (function * (values (simple-array uint31 (*)) &optional)) calc-lis)) (defun calc-lis (as) (declare #.opt ((simple-array uint31 (*)) as)) (let* ((n (length as)) (dp (make-array n :element-type 'uint31 :initial-element 0)) (res (make-array n :element-type 'uint31 :initial-element 0))) (dotimes (i n) (let* ((a (aref as i)) (max (bitree-fold dp a))) (setf (aref res i) (+ max 1)) (bitree-update! dp a (+ max 1)))) res)) (defun main () (declare #.cl-user::opt) (let* ((n (read)) (as (make-array n :element-type 'uint31 :initial-element 0))) (dotimes (i n) (setf (aref as i) (read-fixnum))) (let ((inv-table (make-monotone-inverse-table! (copy-seq as) :test #'eq))) (dotimes (i n) (setf (aref as i) (gethash (aref as i) inv-table))) (let ((max-a (reduce #'max as)) (lis-left (calc-lis as)) (lis-right (nreverse (calc-lis (reverse as))))) (declare (uint31 max-a)) (dotimes (i n) (setf (aref as i) (- max-a (aref as i)))) (let ((lds-left (calc-lis as)) (lds-right (nreverse (calc-lis (reverse as)))) (res 0)) (declare (uint31 res)) (loop for l across lis-left for r across lis-right do (maxf res (- (min l r) 1))) (loop for l across lds-left for r across lds-right do (maxf res (- (min l r) 1))) (println res)))))) #-swank (main) ;;; ;;; Test and benchmark ;;; #+swank (defun get-clipbrd () (with-output-to-string (out) #+os-windows (run-program "powershell.exe" '("-Command" "Get-Clipboard") :output out :search t) #+os-unix (run-program "xsel" '("-b" "-o") :output out :search t))) #+swank (defparameter *this-pathname* (uiop:current-lisp-file-pathname)) #+swank (defparameter *dat-pathname* (uiop:merge-pathnames* "test.dat" *this-pathname*)) #+swank (defun run (&optional thing (out *standard-output*)) "THING := null | string | symbol | pathname null: run #'MAIN using the text on clipboard as input. string: run #'MAIN using the string as input. symbol: alias of FIVEAM:RUN!. pathname: run #'MAIN using the text file as input." (let* ((*standard-output* (or out (make-string-output-stream))) (res (etypecase thing (null (with-input-from-string (*standard-input* (delete #\Return (get-clipbrd))) (main))) (string (with-input-from-string (*standard-input* (delete #\Return thing)) (main))) (symbol (5am:run! thing)) (pathname (with-open-file (*standard-input* thing) (main)))))) (if out res (get-output-stream-string *standard-output*)))) #+swank (defun gen-dat () (uiop:with-output-file (out *dat-pathname* :if-exists :supersede) (format out ""))) #+swank (defun bench (&optional (out (make-broadcast-stream))) (time (run *dat-pathname* out))) ;; To run: (5am:run! :sample) #+swank (it.bese.fiveam:test :sample (it.bese.fiveam:is (equal "1 " (run "3 1 3 2 " nil))) (it.bese.fiveam:is (equal "0 " (run "1 1 " nil))) (it.bese.fiveam:is (equal "2 " (run "6 5 3 1 2 4 2 " nil))))