双指针
class Solution {
public:
vector<int> exchange(vector<int>& nums) {
int left = 0, right = nums.size() - 1;
while (left < right) {
if ((nums[left] & 1) != 0) {
++left;
continue;
}
if ((nums[right] & 1) == 0) {
--right;
continue;
}
std::swap(nums[left++], nums[right--]);
}
return nums;
}
};