基础算法java实现数组反转

Posted 2021-10-10 醉酒的小男人

数组的反转原理和冒泡排序有点像,都是通过交换位置,只不过数组的反转是交换第一个和最后一个的位置,第二个和倒数第二个的位置,冒泡排序是交换相邻两个的位置。

代码实现

package thread;

public class ArrayDemo {

    public static void main(String[] args) {
        String[] arr = {"a","b","c","d","e","f","g"};
        String[] arr1 = reverse(arr);
        for(String elem:arr1){
            System.out.print(elem + "\\t");
        }
        System.out.println();
        System.out.println("=============================");
        String[] arr2 = {"a","b","c","d","e","f","g"};
        String[] arr3 = reverse1(arr2);
        for(String elem:arr3){
            System.out.print(elem + "\\t");
        }
    }

    public static String[] reverse(String[] arr){
        for(int i = 0; i < arr.length/2;i++){
            String temp = arr[arr.length -1 -i];
            arr[arr.length - 1 - i] = arr[i];
            arr[i] = temp;
        }
        return arr;
    }

    // 第二种方式
    public static String[] reverse1(String[] arr){
        String[] newArr = new String[arr.length];
        for(int i = arr.length-1;i >= 0;i--){
            newArr[arr.length-i-1] = arr[i];
        }
        return newArr;
    }

}

执行结果: