package com.meritit.sortord.util;
/**
* One util to swap tow element of Array
*
* @author ysjian
* @version 1.0
* @email ysjian_pingcx@126.com
* @QQ 646633781
* @telephone 18192235667
* @csdnBlog http://blog.csdn.net/ysjian_pingcx
* @createTime 2013-12-20
* @copyRight Merit
*/
public class Swapper {
private Swapper() {
}
/**
* Swap tow elements of the array
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param array
* the array to be swapped
* @exception NullPointerException
* if the array is null
*/
public static <T extends Comparable<T>> void swap(int oneIndex,
int anotherIndex, T[] array) {
if (array == null) {
throw new NullPointerException("null value input");
}
checkIndexs(oneIndex, anotherIndex, array.length);
T temp = array[oneIndex];
array[oneIndex] = array[anotherIndex];
array[anotherIndex] = temp;
}
/**
* Swap tow elements of the array
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param array
* the array to be swapped
* @exception NullPointerException
* if the array is null
*/
public static void swap(int oneIndex, int anotherIndex, int[] array) {
if (array == null) {
throw new NullPointerException("null value input");
}
checkIndexs(oneIndex, anotherIndex, array.length);
int temp = array[oneIndex];
array[oneIndex] = array[anotherIndex];
array[anotherIndex] = temp;
}
/**
* Check the index whether it is in the arrange
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param arrayLength
* the length of the Array
* @exception IllegalArgumentException
* if the index is out of the range
*/
private static void checkIndexs(int oneIndex, int anotherIndex,
int arrayLength) {
if (oneIndex < 0 || anotherIndex < 0 || oneIndex >= arrayLength
|| anotherIndex >= arrayLength) {
throw new IllegalArgumentException(
"illegalArguments for tow indexs [" + oneIndex + ","
+ oneIndex + "]");
}
}
}
