LintCode "Partition Array by Odd and Even"

class Solution {
public:
    /**
    * @param nums: a vector of integers
    * @return: nothing
    */
    void partitionArray(vector<int> &nums) {
        size_t len = nums.size();
        int i = 0, io = 0, ie = len - 1;
        while (io < ie)
        {
            int v = nums[i];
            if (v & 0x1) // odd
            {
                swap(nums[i], nums[io++]);
            }
            else    // even
            {
                swap(nums[i], nums[ie--]);
            }
            i = io;
        }
    }
};