我试图了解这个基数排序算法是如何工作的。我是算法和位的新手，所以这对我来说并不容易。到目前为止，我已将这些注释添加到我的代码中，以尝试使其更易于理解。我不确定我是否正确掌握了这个概念，所以如果有人看到我的评论有任何问题/我不正确理解的东西，请帮助我:)
任何人都可以向我解释这行代码：mask = 1 << bit;
我的评论代码：
public static ArrayList<Integer> RadixSort(ArrayList<Integer> a)
//This method implements the radix sort algorithm, taking an integer array as an input
{
ArrayList<Integer> array = CopyArray(a);
//Created a new integer array called 'array' and set it to equal the array inputed to the method
//This was done by copying the array entered to the method through the CopyArray method, then setting the results of the method to the new empty array
Integer[] zerobucket = new Integer[a.size()];
Integer[] onebucket = new Integer[a.size()];
//Created two more integer arrays to act as buckets for the binary values
//'zerobucket' will hold array elements where the ith bit is equal to 0
//'onebucket' will hold array elements where the ith bit is equal to 1
int i, bit;
//Created two integer variables i & bit, these will be used within the for loops below
//Both i & bit will be incremented to run the radix sort for every bit of the binary value, for every element in the array
Integer element, mask;
//Created an integer object called element, this will be used to retrieve the ith element of the unsorted array
//Created an integer object called mask, this will be used to compare the bit values of each element
for(bit=0; bit<8; ++bit)
//Created a for loop to run for every bit of the binary value e.g.01000000
//Change from 8 to 32 for whole integers - will run 4 times slower
{
int zcount = 0;
int ocount = 0;
//Created two integer variables to allow the 'zerobucket' and 'onebucket' arrays to be increment within the for loop below
for(i=0; i<array.size(); ++i)
//Created a nested for loop to run for every element of the unsorted array
//This allows every bit for every binary value in the array
{
element = array.get(i);
//Set the variable 'element' to equal the ith element in the array
mask = 1 << bit;
if ((element & mask) == 0)
//If the selected bit of the binary value is equal to 0, run this code
{
zerobucket[zcount++] = array.get(i);
//Set the next element of the 'zerobucket' array to equal the ith element of the unsorted array
}
else
//Else if the selected but of the binary value is not equal to 0, run this code
{
onebucket[ocount++] = array.get(i);
//Set the next element of the 'onebucket' array to equal the ith element of the unsorted array
}
}
for(i=0; i<ocount; ++i)
//Created a for loop to run for every element within the 'onebucket' array
{
array.set(i,onebucket[i]);
//Appended the ith element of the 'onebucket' array to the ith position in the unsorted array
}
for(i=0; i<zcount; ++i)
//Created a for loop to run for every element within the 'zerobucket' array
{
array.set(i+ocount,zerobucket[i]);
//Appended the ith element of the 'zerobucket' array to the ith position in the unsorted array
}
}
return(array);
//Returned the sorted array to the method
}
我没有写这段代码我被赋予它试图理解