剑指offer T21调整数组顺序使奇数位于前半段，偶数位于后半段

class Solution {
    /*
    使用双指针
    */
    public int[] exchange(int[] nums) {
    if(nums.length==0) return nums;    
    int left = 0,right = nums.length-1;
    while(leftleft&&nums[right]%2==0){
            right--;
        }
        int temp = nums[left];
        nums[left] = nums[right];
        nums[right] = temp;
        left++;
        right--;
    }
    return nums;
    }
}