/*license*\
XBN-Java Library
Copyright (c) 2014, Jeff Epstein (aliteralmind __DASH__ github __AT__ yahoo __DOT__ com)
This software is dual-licensed under the:
- Lesser General Public License (LGPL) version 3.0 or, at your option, any later version;
- Apache Software License (ASL) version 2.0.
Either license may be applied at your discretion. More information may be found at
- http://en.wikipedia.org/wiki/Multi-licensing.
The text of both licenses is available in the root directory of this project, under the names "LICENSE_lgpl-3.0.txt" and "LICENSE_asl-2.0.txt". The latest copies may be downloaded at:
- LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt
- ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt
\*license*/
package com.github.xbn.examples.util.non_xbn;
/**
<p>Function that returns true if a string has exactly four (or however many) unique characters--uniqueness is detected with a {@code Map<Character,Object>}, where the value is always {@code null}.</p>
<p>{@code java com.github.xbn.examples.util.non_xbn.FirstDifferentCharIndex}</p>
* @since 0.1.0
* @author Copyright (C) 2014, Jeff Epstein ({@code aliteralmind __DASH__ github __AT__ yahoo __DOT__ com}), dual-licensed under the LGPL (version 3.0 or later) or the ASL (version 2.0). See source code for details. <a href="http://xbnjava.aliteralmind.com">{@code http://xbnjava.aliteralmind.com}</a>, <a href="https://github.com/aliteralmind/xbnjava">{@code https://github.com/aliteralmind/xbnjava}</a>
**/
import java.util.Map;
import java.util.TreeMap;
/**
<p>{@code java ExactlyFourDiffChars}</p>
**/
public class ExactlyFourDiffChars {
public static final void main(String[] ignored) {
System.out.println("aabbccdd: " + hasMoreThanXUniqueChars(4, "aabbccdd"));
System.out.println("dictionary: " + hasMoreThanXUniqueChars(4, "dictionary"));
System.out.println("reassesses: " + hasMoreThanXUniqueChars(4, "reassesses"));
}
public static final boolean hasMoreThanXUniqueChars(int maxAllowedChars, String str) {
Map<Character,Object> charMap = new TreeMap<Character,Object>();
for(int i = 0; i < str.length(); i++) {
Character C = str.charAt(i);
if(!charMap.containsKey(C)) {
charMap.put(C, null);
if(maxAllowedChars-- == 0) {
return false;
}
}
}
return true;
}
}