1.动图演示：

2.代码示例：

package test1;

import java.util.Arrays;

public class Test3 {
    public static void main(String[] args) {
        int[] nums = new int[]{1, 2, 1, 4, 52, 1, 4};
        int[] arr = count_sort(nums, getMax(nums));
        for (int i : arr) {
            System.out.print(i + " ");
        }
    }

    public static int getMax(int[] nums) {
        int max = nums[0];
        for (int num : nums) {
            if (max < num) {
                max = num;
            }
        }
        return max;
    }

    public static int[] count_sort(int[] nums, int max) {
        int[] arr = Arrays.copyOf(nums, nums.length);
        int[] bucket = new int[max + 1];
        for (int val : arr) {
            bucket[val]++;
        }

        int sortedIndex = 0;
        for (int i = 0; i < bucket.length; i++) {
            while (bucket[i] > 0) {
                arr[sortedIndex++] = i;
                bucket[i]--;
            }
        }
        return arr;
    }
}