460. find k closest elements

public class  {
    
     * @param A: an integer array
     * @param target: An integer
     * @param k: An integer
     * @return: an integer array
     */
    public int[] kClosestNumbers(int[] A, int target, int k) {
        // write your code here
        if (A == null || A.length == 0 || k == 0) {
            return new int[0];
        }
        int start = 0, end = A.length - 1;
        while (start + 1 < end) {
            int mid = start + (end - start) / 2;
            if (A[mid] < target) {
                start = mid;
            } else {
                end = mid;
            }
        }
        // find the range of target
        /*
        如果target out of range, 一边的point不会动。
        */

        int[] result = new int[k];
        int count = 0;
        while (start >= 0 && end <= A.length - 1 && count < k) {
            // start更接近target
            if (Math.abs(A[start] - target) <= Math.abs(A[end] - target)) {
                result[count] = A[start];
                start--;
            } else {
                result[count] = A[end];
                end++;
            }
            count++;
        }
        // count 有可能没有填满
        while (count < k && start >= 0) {
            result[count] = A[start];
            count++;
            start--;
        }
        while (count < k && end <= A.length - 1) {
            result[count] = A[end];
            count++;
            end++;
        }
        return result;

    }
}