用于计数排序的Java程序

计数排序是一种基于特定范围之间的键的排序技术。它通过计算具有不同键值(哈希类型)的对象的数量来工作。然后做一些算术计算每个对象在输出序列中的位置。

// Java implementation of Counting Sort
class CountingSort {
    void sort(char arr[])
    {
        int n = arr.length;
  
        // The output character array that will have sorted arr
        char output[] = new char[n];
  
        // Create a count array to store count of inidividul
        // characters and initialize count array as 0
        int count[] = new int[256];
        for (int i = 0; i < 256; ++i)
            count[i] = 0;
  
        // store count of each character
        for (int i = 0; i < n; ++i)
            ++count[arr[i]];
  
        // Change count[i] so that count[i] now contains actual
        // position of this character in output array
        for (int i = 1; i <= 255; ++i)
            count[i] += count[i - 1];
  
        // Build the output character array
        for (int i = 0; i < n; ++i) {
            output[count[arr[i]] - 1] = arr[i];
            --count[arr[i]];
        }
  
        // Copy the output array to arr, so that arr now
        // contains sorted characters
        for (int i = 0; i < n; ++i)
            arr[i] = output[i];
    }
  
    // Driver method
    public static void main(String args[])
    {
        CountingSort ob = new CountingSort();
        char arr[] = {'g', 'e', 'e', 'k', 's', 'f', 'o',
                      'r', 'g', 'e', 'e', 'k', 's' };
  
        ob.sort(arr);
  
        System.out.print("Sorted character array is ");
        for (int i = 0; i < arr.length; ++i)
            System.out.print(arr[i]);
    }
}
/*This code is contributed by Rajat Mishra */

输出：

Sorted character array is eeeefggkkorss

请参阅关于计数排序的完整文章以获取更多详细信息！