Here you can find the source of shift(String s, int length, List
private static void shift(String s, int length, List<String> list, StringBuffer res)
//package com.java2s; /**/* ww w.ja v a 2 s. co m*/ * MIT License * * Copyright (c) 2017 Vladimir Mikhaylov * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. **/ import java.util.List; public class Main { private static void shift(String s, int length, List<String> list, StringBuffer res) { if (length == 0) { if (!list.contains(res.toString())) { list.add(res.toString()); } } else { for (int i = 0; i < s.length(); i++) { String news = s.substring(0, i) + s.substring(i + 1, s.length()); String simb = s.substring(i, i + 1); shift(news, length - 1, list, (new StringBuffer(res)).append(simb)); } } } }