Java中冒泡排序与二分查找

1. Java中冒泡排序

public class BubbleSortTest{
    public static void bubbleSort(int[] array){
        for(int i = 0; i < array.length - 1; i++){
            for(int j = 0; j < array.length - i - 1; j++){
                if(array[j] > array[j + 1]){
                    int temp = array[j];
                    array[j] = array[j + 1];
                    array[j + 1] = temp;
                }
            }
            System.out.print("第" + (i + 1) + "趟排序：");
            for(int k = 0; k < array.length; k++){
                System.out.print(array[k] + " ");
            }
            System.out.println();
        }
    }
    public static void main(String[] args){
        int[] array = {4, 7, 8, 9, 3, 2};
        bubbleSort(array);
    }
}
运行结果：
第1趟排序：4 7 8 3 2 9 
第2趟排序：4 7 3 2 8 9 
第3趟排序：4 3 2 7 8 9 
第4趟排序：3 2 4 7 8 9 
第5趟排序：2 3 4 7 8 9 

2. Java中二分查找

public class ArraySearchTest{
    public static int search(int[] array, int value){
        for(int i = 0; i < array.length; i++){
            if(value == array[i]){
                return i;
            }
        }
        return -1;
    }
    public static int binarySearch(int[] array, int value){
        int low = 0;
        int high = array.length - 1;
        int middle;
        while(low <= high){
            middle = (low + high) / 2;
            for(int i = 0; i < array.length; i++){
                System.out.print(array[i]);
                if(i == middle){
                    System.out.print("#");
                }
                System.out.print(" ");
            }
            System.out.println();
            if(array[middle] == value){
                return middle;
            }
            if(value < array[middle]){
                high = middle - 1;
            }
            if(value > array[middle]){
                low = middle + 1;
            }
        }
        return -1;
    }
    public static void main(String[] args){
        int[] a = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
        int value = 8;
        int index = search(a, value);
        System.out.println(index);
        System.out.println("-----------------");
        int[] b = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9};
        int index2 = binarySearch(b , 4);
        System.out.println(index2);
    }
}
运行结果：
7
-----------------
1 2 3 4 5# 6 7 8 9 
1 2# 3 4 5 6 7 8 9 
1 2 3# 4 5 6 7 8 9 
1 2 3 4# 5 6 7 8 9 
3