Java List Rotate rotate(final List list, int n)

Description

Rotate a list by N places.

License

Open Source License

Parameter

Parameter	Description
list	The <code>List</code> to rotate.
n	The number of places to rotate by (positive or negative).

Declaration

public static <T> void rotate(final List<T> list, int n) 

Method Source Code

//package com.java2s;
/**//from   w  w w  .java  2 s  .co  m
 *  Copyright (C) 2002-2015   The FreeCol Team
 *
 *  This file is part of FreeCol.
 *
 *  FreeCol is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  FreeCol 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.util.List;

public class Main {
    /**
     * Rotate a list by N places.
     *
     * @param list The <code>List</code> to rotate.
     * @param n The number of places to rotate by (positive or negative).
     */
    public static <T> void rotate(final List<T> list, int n) {
        final int len = list.size();
        if (len <= 0 || n == 0)
            return;
        n %= len;
        if (n > 0) {
            for (; n > 0; n--) {
                T t = list.remove(0);
                list.add(t);
            }
        } else {
            for (; n < 0; n++) {
                T t = list.remove(n - 1);
                list.add(0, t);
            }
        }
    }
}

Related

1. rotate(List