分治-快排系列一＞颜色划分

class Solution {
   public void sortColors(int[] nums){
        int left = -1, right = nums.length,i = 0;
        while(i < right){
            if(nums[i] == 0) swap(nums, i++, ++left);
            else if(nums[i] == 1) i++;
            else swap(nums, i, --right);
        }
   }

   private void swap(int[] nums, int i, int j){
        int t = nums[i];
        nums[i] = nums[j];
        nums[j] = t;
   }
}