. - 力扣（LeetCode）

class Solution {
public:
    vector<int> smallestK(vector<int>& nums, int k) {
        int L = 0, R = nums.size() - 1;
        while (L < R)
        {
            int left = L, right = R;
            int key = nums[left];
            while (left < right)
            {
                while (left < right && nums[right] >= key)
                    --right;
                nums[left] = nums[right];
                while (left < right && nums[left] <= key)
                    ++left;
                nums[right] = nums[left];
            }
            nums[left] = key;
            if (left == k - 1)
                return vector<int> (nums.begin(), nums.begin() + k);
            else if (left > k - 1)
                R = left - 1;
            else
                L = left + 1;
        }
        return vector<int> (nums.begin(), nums.begin() + k);

    }
};