LC 658. 找到 K 个最接近的元素

class Solution {
   public:
    vector<int> findClosestElements(vector<int>& arr, int k, int x) {
        int ax = 0;
        vector<int> res(k);
        int m = abs(arr[0] - x);
        for (int i = 0; i < arr.size(); i++) {
            if (abs(arr[i] - x) < m) {
                m = abs(arr[i] - x);
                ax = i;
            }
        }
        int num = 1;
        int left = ax - 1;
        int right = ax + 1;
        while (num < k) {
            if (left < 0) {
                right += k - num;
                break;
            }
            if (right >= arr.size()) {
                left -= k - num;
                break;
            }
            while (num < k && left >= 0 && right < arr.size() &&
                   x - arr[left] <= arr[right] - x) {
                left--;
                num++;
            }
            while (num < k && left >= 0 && right < arr.size() &&
                   x - arr[left] > arr[right] - x) {
                right++;
                num++;
            }
        }
        int j = 0;
        for (int i = left + 1; i < right; i++) {
            res[j++] = arr[i];
        }
        return res;
    }
};