java算法系列

public class SortTest {
    public static void main(String[] args) {
        int[] array = {2, 5, 1, 7, 4, 9, 3};
        insertionSort(array);
        System.out.println(Arrays.toString(array));
    }

    
    public static void insertionSort(int[] array) {
        //需要 0~i 有序 0~0本就有序,所以从1开始
        for (int i = 1; i < array.length; i++) {
            for (int j = i - 1; j >= 0 && array[j] > array[j + 1]; j--) {
                int tem = array[j];
                array[j] = array[j + 1];
                array[j + 1] = tem;
            }
        }
    }

    
    public static void bubbleSort(int[] array) {
        //控制每轮的次数
        for (int x = 0; x < array.length - 1; x++) {
            for (int i = 0; i < array.length - 1 - x; i++) {
                if (array[i] > array[i + 1]) {
                    int tem = array[i];
                    array[i] = array[i + 1];
                    array[i + 1] = tem;
                }
            }
        }
    }

    
    public static void selectSort(int[] array) {
        for (int i = 0; i < array.length - 1; i++) {
            for (int j = i + 1; j < array.length; j++) {
                if (array[i] > array[j]) {
                    int tem = array[i];
                    array[i] = array[j];
                    array[j] = tem;
                }
            }
        }
    }
}