Java でトップ 10 の並べ替えアルゴリズムを実装する方法

public static void selectionSort(int[] arr){
    //细节一：这里可以是arr.length也可以是arr.length-1
    for (int i = 0; i < arr.length-1 ; i++) {
        int mini = i;
        for (int j = i+1; j < arr.length; j++) {
            //切换条件，决定升序还是降序
            if(arr[mini]>arr[j]) mini =j;
        }
        swap(arr,mini,i);
    }
}

public static void bubbleSort(int[] arr){
    for (int i = 0; i < arr.length-1; i++) {
        //记录本次有没有进行交换的操作
        boolean flag = false;
        //保存在头就动头，保存在尾就动尾
        for(int j =0 ; j < arr.length-1-i ; j++){
            //升序降序选择地
            if(arr[j] > arr[j+1])
            {
                swap(arr,j,j+1);
                flag = true;
            }
        }
        //如果本次没有进行交换操作，表示数据已经有序
        if(!flag){break;} //程序结束
    }
}

public static void insertSort(int[] arr){
        //从第二个数开始，把每个数依次插入到指定的位置
        for(int i = 1 ; i < arr.length ; i++)
        {
            int key = arr[i];
            int j = i-1;
            //大的后移操作
            while(j >= 0 && arr[j] > key)
            {
                arr[j+1] = arr[j];
                j--;
            }
            arr[j+1] = key;
        }
    }

public static void shellSort(int[] arr){
        //分块处理
        int gap = arr.length/2; //增量
        while(1<=gap)
        {
            //插入排序：只不过是与增量位交换
            for(int i = gap ; i < arr.length ; i++)
            {
                int key = arr[i];
                int j = i-gap;
                while(j >= 0 && arr[j] > key)
                {
                    arr[j+gap] = arr[j];
                    j-=gap;
                }
                arr[j+gap] = key;
            }
            gap = gap/2;
        }
    }

//堆排序
    public static void heapSort(int[] arr){
        //开始调整的位置为最后一个叶子节点
        int start = (arr.length - 1)/2;
        //从最后一个叶子节点开始遍历，调整二叉树
        for (int i = start; i >= 0 ; i--){
            maxHeap(arr, arr.length, i);
        }
 
        for (int i = arr.length - 1; i > 0; i--){
            int temp = arr[0];
            arr[0] = arr[i];
            arr[i] = temp;
            maxHeap(arr, i, 0);
        }
    }
 
    //将二叉树调整为大顶堆
    public static void maxHeap(int[] arr, int size, int index){
        //建立左子节点
        int leftNode = 2 * index + 1;
        //建立右子节点
        int rightNode = 2 * index + 2;
 
        int maxNode = index;
        //左子节点的值大于根节点时调整
        if (leftNode < size && arr[leftNode] > arr[maxNode]){
            maxNode = leftNode;
        }
        //右子节点的值大于根节点时调整
        if (rightNode < size && arr[rightNode] > arr[maxNode]){
            maxNode = rightNode;
        }
        if (maxNode != index){
            int temp = arr[maxNode];
            arr[maxNode] = arr[index];
            arr[index] = temp;
            //交换之后可能会破坏原来的结构，需要再次调整
            //递归调用进行调整
            maxHeap(arr, size, maxNode);
        }
    }

public static void mergeSort(int[] arr, int low, int high){
        int middle = (high + low)/2;
        if (low < high){
            //递归排序左边
            mergeSort(arr, low, middle);
            //递归排序右边
            mergeSort(arr, middle +1, high);
            //将递归排序好的左右两边合并
            merge(arr, low, middle, high);
        }
 
    }
 
    public static void merge(int[] arr, int low, int middle, int high){
        //存储归并后的临时数组
        int[] temp = new int[high - low + 1];
        int i = low;
        int j = middle + 1;
        //记录临时数组中存放数字的下标
        int index = 0;
        while (i <= middle && j <= high){
            if (arr[i] < arr[j]){
                temp[index] = arr[i];
                i++;
            } else {
                temp[index] = arr[j];
                j++;
            }
            index++;
        }
        //处理剩下的数据
        while (j <= high){
            temp[index] = arr[j];
            j++;
            index++;
        }
        while (i <= middle){
            temp[index] = arr[i];
            i++;
            index++;
        }
        //将临时数组中的数据放回原来的数组
        for (int k = 0; k < temp.length; ++k){
            arr[k + low] = temp[k];
        }
    }

	//快速排序
	public static void QuickSort1(int[] arr, int start, int end){
		int low = start, high = end;
		int temp;
		if(start < end){
		    int guard = arr[start];
			while(low != high){
				while(high > low && arr[high] >= guard) high--;
				while(low < high && arr[low] <= guard) low++;
				if(low < high){
					temp = arr[low];
					arr[low] = arr[high];
					arr[high] = temp;
				}
			}
			arr[start] = arr[low];
			arr[low] = guard;
			QuickSort1(arr, start, low-1);
			QuickSort1(arr, low+1, end);
		}
	}
	
	//快速排序改进版(填坑法)
	public static void QuickSort2(int[] arr, int start, int end){
		int low = start, high = end;
		if(start < end){
		while(low != high){
	    	int guard = arr[start];//哨兵元素
			while(high > low && arr[high] >= guard) high--;
			arr[low] = arr[high];
			while(low < high && arr[low] <= guard) low++;
			arr[high] = arr[low];
		}
		arr[low] = guard;
		QuickSort2(arr, start, low-1);
		QuickSort2(arr, low+1, end);
	}
}

//鸽巢排序
    public static void PigeonholeSort(int[] arr){
        //获取最大值
        int k = 0;
        for (int i = 0; i < arr.length; i++) {
            k = Math.max(k,arr[i]);
        }
        //创建计数数组并且初始化为0
        int[] cnt = new int[k+10];
        for(int i = 0 ; i <= k ; i++) { cnt[i]=0; }
        for(int i = 0 ; i < arr.length ;i++) { cnt[arr[i]]++; }
        int j = 0;
        for(int i = 0 ; i <=k ; i++)
        {
            while(cnt[i]!=0)
            {
                arr[j]=i;
                j++;
                cnt[i]--;
            }
        }
    }

//基数排序
    public static void radixSort(int[] array) {
        //基数排序
        //首先确定排序的趟数;
        int max = array[0];
        for (int i = 1; i < array.length; i++) {
            if (array[i] > max) {
                max = array[i];
            }
        }
        int time = 0;
        //判断位数;
        while (max > 0) {
            max /= 10;
            time++;
        }
        //建立10个队列;
        List<ArrayList> queue = new ArrayList<ArrayList>();
        for (int i = 0; i < 10; i++) {
            ArrayList<Integer> queue1 = new ArrayList<Integer>();
            queue.add(queue1);
        }
        //进行time次分配和收集;
        for (int i = 0; i < time; i++) {
            //分配数组元素;
            for (int j = 0; j < array.length; j++) {
                //得到数字的第time+1位数;
                int x = array[j] % (int) Math.pow(10, i + 1) / (int) Math.pow(10, i);
                ArrayList<Integer> queue2 = queue.get(x);
                queue2.add(array[j]);
                queue.set(x, queue2);
            }
            int count = 0;//元素计数器;
            //收集队列元素;
            for (int k = 0; k < 10; k++) {
                while (queue.get(k).size() > 0) {
                    ArrayList<Integer> queue3 = queue.get(k);
                    array[count] = queue3.get(0);
                    queue3.remove(0);
                    count++;
                }
            }
 
        }
 
 
    }