https://bbs.fanruan.com/wenda/question/171958.html 结合你上一个提问
MAPARRAY(SPLIT("aaa,bbb,ccc,",","),CONCATENATE(ITEM,IF(INARRAY(ITEM, SPLIT("aaa,bbb,ccc,",","))%2==0,"",INARRAY(ITEM, SPLIT("aaa,bbb,ccc,",",")))))
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MAPARRAY(SPLIT("aaa,bbb,ccc,",","),IF(INARRAY(ITEM, SPLIT("aaa,bbb,ccc,",","))%2==0,ITEM,CONCATENATE("B",MID(ITEM,2,LEN(ITEM)))))