排序算法

blic class MarquisSort

{

    private static int[] resultData;
    public static void main( String[] args )

    {
        int MAX = 10000000;
        int[] nums = new int[ MAX ];
        Random r = new Random( 20080623 );
        for( int i = 0; i < MAX; i++ )
        {
            nums[ i ] = r.nextInt( MAX );
        }
        long begin = System.currentTimeMillis();
        int[] data = sort( nums );    //排序结果
        long end = System.currentTimeMillis();
        System.out.println( ( end - begin ) ); //排序时间
    }



    public static int[] sort( int[] nums )

    {
        resultData = new int[nums.length];

        countingSort( nums, resultData, getMaxInt( nums ) );

        return resultData;
    }

    

    private static int getMaxInt( int[] data )

    {
        int max = 0;

        for( int i : data )

        {

            if( i > max )

            {

                max = i;

            }

        }

        return max;

    }

    private static void countingSort( int[] oriData, int[] resultData, int k )

    {

        int[] assistData = new int[ k + 1 ];

        

        for( int i = 0; i < assistData.length ; i++ )

        {

            assistData[ i ] = 0;

        }

        

        for( int j = 0; j < oriData.length ; j++ )

        {

            assistData[ oriData[ j ] ] = assistData[ oriData[ j ] ] + 1;

        }



        for( int i = 1; i < assistData.length ; i++ )

        {

            assistData[ i ] = assistData[ i ] +  assistData[ i - 1 ];

        }



        for( int j = oriData.length - 1  ; j >= 0 ; j-- )

        {

            resultData[ assistData[ oriData[ j ] ] - 1 ] = oriData[ j ];

            assistData[ oriData[ j ] ] = assistData[ oriData[ j ] ] - 1;

        }    

    }



}