From 521f7d098e8854dadf6afc892423ad5678bfa8fa Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Mon, 20 Jan 2014 02:55:27 +0100 Subject: add min max MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/algorithms/bits/MinMax.java | 72 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 src/algorithms/bits/MinMax.java (limited to 'src/algorithms/bits') diff --git a/src/algorithms/bits/MinMax.java b/src/algorithms/bits/MinMax.java new file mode 100644 index 0000000..624ea57 --- /dev/null +++ b/src/algorithms/bits/MinMax.java @@ -0,0 +1,72 @@ +/** + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + */ +package algorithms.bits; + + +/** + * Compute the minimum or maximum of two integers + */ +public class MinMax +{ +£S=${T_S#*_} + /** + * Compute the minimum of two integers + * + * @param a One of the integers + * @param b The other of the integers + * @return The minimum of the two integers + */ + public static £{T} min(£{T} a, £{T} b) + { + return (£{T})(b ^ (£{T})((a ^ b) & ((a - b) >> £{S}))); + /* In C you can also do: + * b ^ ((a ^ b) & -(a < b)) + */ + /* + * Other version that can be faster: + * (a < b) ? a : b + * Assuming you now that INT_MIN <= x - y <= INT_MAX: + * b + ((a - b) & ((a - b) >> (sizeof(£{T}) * CHAR_BITS - 1))) + */ + } + + /** + * Compute the maximum of two integers + * + * @param a One of the integers + * @param b The other of the integers + * @return The maximum of the two integers + */ + public static £{T} max(£{T} a, £{T} b) + { + return (£{T})(a ^ (£{T})((a ^ b) & ((a - b) >> £{S}))); + /* In C you can also do: + * a ^ ((a ^ b) & -(a < b)) + */ + /* + * Other version that can be faster: + * (a < b) ? b : a + * Assuming you now that INT_MIN <= x - y <= INT_MAX: + * a - ((a - b) & ((a - b) >> (sizeof(£{T}) * CHAR_BITS - 1))) + */ + } + +£>done +} + -- cgit v1.2.3-70-g09d2