double [] array = {4,3,6,5,9,6,5}; 

        //保留陣列的初始下標
        int[] index_init = new int[array.length];
        for (int i = 0; i < index_init.length; i++) 
        {
            index_init[i] = i;
        }

        for (int i = 0; i < array.length-1; i++) //降序排序
        {
            for
 
 (int j = i+1; j < array.length; j++) 
            {
                if(array[i]<array[j])
                {
                    double temp = array[i]; 
                    array[i] = array[j];
                    array[j] = temp;

                    int p = index_init[i];
                    index_init[i] = index_init[j];
                    index_init[j] = p;
                }

            }
        }

    System.out.println(Arrays.toString(array
 
));
    System.out.println(Arrays.toString(index_init));

經過處理後的array降序排列，而index_init中的元素與array一一對應，index_init[i]即為array[i]在排序前陣列中的下標。