入门排序

新手入门级排序

1.冒泡排序

public class BolloSort {
   
    public static void main(String[] args) {
   
        int[] array = {
   5, 4, 2, 6, 4, 21, 1};
        System.out.println("排序前" + Arrays.toString(array));

       for (int i = 0, len = arrays.length; i < len; i++) {
   
            for (int j = 0; j < len - i - 1; j++) {
   
                if (arrays[j] > arrays[j + 1]) {
   
                    int temp = arrays[j];
                    arrays[j] = arrays[j + 1];
                    arrays[j + 1] = temp;
                }
            }
        }
        System.out.println("排序后" + Arrays.toString(array));
    }

}

2.选择排序

public class SelectSort {
   
    public static void main(String[] args) {
   
        int[] array = {
   5, 4, 2, 6, 4, 21, 1};
        System.out.println("排序前" + Arrays.toString(array));

        for (int tian = array.length - 1; tian >= 0; tian--) {
   
            int max = array[0];
            int maxIndex = 0;
            for (int i = 0; i <= tian; i++) {
   
                if (array[i] > max) {
   
                    max = array[i];
                    maxIndex = i;
                }
            }
            int temp = array[tian];
            array[tian] = array[maxIndex];
            array[maxIndex] = temp;
        }
        System.out.println("排序后" + Arrays.toString(array));
    }

}

3.插入排序

public class InsertSotr {
    public static void main(String[] args) {
        int[] array = {5, 4, 2, 6, 4, 21, 1};
        System.out.println("排序前" + Arrays.toString(array));
        for (int i = 0; i < array.length; i++) {
            int lastIndex = i-1;
            int v = array[i];
            while(lastIndex>-1&&v<array[lastIndex]){
                array[lastIndex+1] =array[lastIndex];
                lastIndex--;
            }
            array[lastIndex+1] = v;
        }
        System.out.println("排序前" + Arrays.toString(array));
    }
}