java数组常见的编程题 java数组的题目

1. 给定两个整型数组, 交换两个数组的内容.

import java.util.Arrays;

class Test {
    public static void main(String[] args) {
        int[] arr1 = {1,2,3,4,5,6};
        int[] arr2 = {2,3,4,5,6,7};
        int tmp = 0;
        for (int i = 0; i < arr1.length; i++) {
            tmp = arr1[i];
            arr1[i] = arr2[i];
            arr2[i] = tmp;
        }
        System.out.println("arr1 : " + Arrays.toString(arr1));
        System.out.println("arr2 : " + Arrays.toString(arr2));
        }
    }

2.给定整型数组, 把所有的偶数放到数组前面, 把所有奇数放到数组后面.

import java.util.Arrays;

public class Test {
    //给定整型数组, 把所有的偶数放到数组前面, 把所有奇数放到数组后面.
    public static void main(String[] args) {
        int[] arr = {1,2,3,5,6,4,7,8,9};
        int left = 0;
        int right = arr.length - 1;
        while (left < right) {
            while (left < right && arr[left] % 2 == 0) {
                left++;
            }
            while (left < right && arr[right] % 2 != 0) {
                right--;
            }
            int tmp = arr[left];
            arr[left] = arr[right];
            arr[right] = tmp;
        }
        System.out.println(Arrays.toString(arr));
    }
}