EXCEL 求选定区域内不重复数据的个数

Counting number of unique entries in a specified range.  
By using SUMPRODUCT along with COUNT to count only the number
of unique entries in a specified range.
The range can be all in one column or row, or may span multiple (adjoining) columns/rows.
The formula would be written as: =SUMPRODUCT((1/COUNTIF(A1:C5,A1:C5)))
where A1:C5 is replaced with the range you want to apply the count to

求选定区域内不重复数据的个数的解题思路
1.用sumproduct函数配合countif函数求解
2.用sum函数配合countif函数求解,写完公式后按ctrl+shift+enter(数组公式)