Java实现常见算法

public class SortMethod {

    
    public static void bubbleSort(int[] arr) {
        int size = arr.length;
        boolean f = true;
        for (int i = 0; i < size - 1; i++) {
            for (int j = 0; j < size - 1; j++) {
                if (arr[j] > arr[j + 1]) {
                    int tmp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = tmp;
                    f = false;
                }
            }
            if (f) {
                break;
            }
        }
        printArr(arr);
    }





    
    public static void selectSort(int[] arr) {
        int length = arr.length;
        for (int i = 0; i < length - 1; i++) {
            // 最小值下表
            int minIdx = i;
            // 最小值
            int minVal = arr[i];
            for (int j = i; j < length - i - 1; j++) {
                if (arr[j] < minVal) {
                    minIdx = j;
                    minVal = arr[j];
                }
            }
            arr[minIdx] = arr[i];
            arr[i] = minVal;
        }
        printArr(arr);
    }




    
    public static void insertSort(int[] arr) {
        int length = arr.length;
        for (int i = 1; i < length - 1; i++) {
            int j = i;
            int value = arr[i];
            while (j > 0 && arr[j] < arr[j - 1]) {
                arr[j] = arr[j - 1];
                arr[j - 1] = value;
                j--;
            }
        }
        printArr(arr);
    }





    
    public static void shellSort(int[] arr) {
        int length = arr.length;
        int step = length;
        do {
            step = step / 3 + 1;
            for (int i = step; i < length - 1; i += step) {
                int value = arr[i];
                while (i - step >= 0 && arr[i - step] > value) {
                    arr[i] = arr[i - step];
                    arr[i - step] = value;
                    i -= step;
                }
            }
        } while (step > 1);

        printArr(arr);
    }





    
    private static void printArr(int[] arr) {
        for (int i = 0; i < arr.length; i++) {
            System.out.println(arr[i]);
        }
    }




    public static void main(String[] args) {
        int[] arr = {0, -1, 7, -4, 8, 12, 10};
        bubbleSort(arr);
        selectSort(arr);
        insertSort(arr);
        shellSort(arr);
        shellSort(arr);
    }
}