题解 | #数字在升序数组中出现的次数#

    public int GetNumberOfK(int [] array , int k) {
       if(array == null || array.length == 0){
           return 0;
       }
        int left = 0;
        int right = array.length - 1;
        int mid = -1;
        int index = -1;
        while(right >= left){
            mid = (right - left) / 2 + left;
            if(k > array[mid]){
                left = mid +1;
            }else if(k < array[mid]){
                right = mid - 1;
            }else{
                index = mid;
                break;
            }
        }
        if(index == -1){
            return 0;
        }
        while(left <= index){
            if(array[left] !=k){
                left ++;
            }else{
                break;
            }
        }
        while(right >= index){
            if(array[right] != k){
                right --;
            }else{
                break;
            }
        }
        return right - left + 1;
    }
}