从9 .csv文件C ++中读取和处理数据

I am currently having issue with trying to read and manipulate data from 9 .csv files, i was able to do it with 1 however i don't know how to do it with 9 data file. Below is the code on how i did it with 1 data file and i find it impractical to repeat it 9 times. Could anyone advise me?I am currently having issue with trying to read