1、前言

2、思路

3、代码

class Solution {
      public int[] exchange(int[] nums) {
        if(nums == null || nums.length == 0){
            return new int[]{};
        }
        int left = 0, right = nums.length - 1;
        while(left < right){
            if(nums[left] % 2 != 0){
                left++;
            }else {
                swap(nums, left, right--);
            }
        }
        return nums;
    }
    
    private void swap(int[] nums, int left, int right){
        int temp = nums[left];
        nums[left] = nums[right];
        nums[right] = temp;
    }
}