统计数组元素数量

/// <summary>
        /// 统计数组里0 - len-1的数量
        /// </summary>
        /// <param name="len">长度</param>
        /// <param name="data">需统计的数据</param>
        /// <returns>数组里0 - len-1的数量</returns>
        /// 比如：byte[] 数组的数为 1 2 3 4 5 1 2 3 1 2 1 则len长度为5时返回结果为 int[]{0,4,3,2,1,1}
        public static int[] statisticalData(int len,byte[] data) 
        {
            int[] nums = new int[len];
            foreach (var v in data.GroupBy(x => x).Select(x => new { k = x.Key, c = x.Count() }))
                nums[v.k] = v.c;
            return nums;
        
        }