From 4583516e98a41862560772b23c5e981d5f87272e Mon Sep 17 00:00:00 2001 From: Dibyendu Majumdar Date: Tue, 26 Sep 2023 17:43:36 +0100 Subject: Chapter 2: Arithmetic MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: Cliff Click Co-authored-by: Thalia Archibald Co-authored-by: Yichen Yan Co-authored-by: XmiliaH <45106915+XmiliaH@users.noreply.github.com> Co-authored-by: Tamás Hadházy <85063808+Hels15@users.noreply.github.com> --- src/main/java/com/seaofnodes/simple/Utils.java | 39 ++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 src/main/java/com/seaofnodes/simple/Utils.java (limited to 'src/main/java/com/seaofnodes/simple/Utils.java') diff --git a/src/main/java/com/seaofnodes/simple/Utils.java b/src/main/java/com/seaofnodes/simple/Utils.java new file mode 100644 index 00000000..45f15327 --- /dev/null +++ b/src/main/java/com/seaofnodes/simple/Utils.java @@ -0,0 +1,39 @@ +package com.seaofnodes.simple; + +import java.util.ArrayList; + +public class Utils { + public static RuntimeException TODO() { return TODO("Not yet implemented"); } + public static RuntimeException TODO(String msg) { return new RuntimeException(msg); } + + /** + * Fast, constant-time, element removal. Does not preserve order + * + * @param array ArrayList to modify + * @param i element to be removed + * @return element removed + */ + public static E del(ArrayList array, int i) { + if ( i >= 0 && i < array.size() ) { + E tmp = array.get(i); + E last = array.removeLast(); + if (i < array.size()) array.set(i, last); + return tmp; + } + return null; + } + + /** + * Search a list for an element by reference + * + * @param ary List to search in + * @param x Object to be searched + * @return >= 0 on success, -1 on failure + */ + public static int find( ArrayList ary, E x ) { + for( int i=0; i