1 class Solution{
 2 public:
 3     /**
 4      * @param nums: A list of integer which is 0, 1 or 2 
 5      * @return: nothing
 6      */    
 7     void sortColors(vector<int> &nums) {
 8         // write your code here
 9         int i = 0, j = nums.size();
10         for (int k = 0; k < j; ++k) {
11             if (nums[k] == 0) {
12                 swap(nums[i++], nums[k]);
13             } else if (nums[k] == 2) {
14                 swap(nums[--j], nums[k--]);
15             }
16         }
17     }
18 };