我有一个映射[String,ListString],我想反转它。例如,如果我有像这样的东西
"1" -> List("a","b","c")
"2" -> List("a","j","k")
"3" -> List("a","c")
结果应该是
"a" -> List("1","2","3")
"b" -> List("1")
"c" -> List("1","3")
"j" -> List("2")
"k" -> List("2")
我试过了:
m.map(_.swap)
但它返回一个映射[ListString,字符串]:
List("a","b","c") -> "1"
List("a","j","k") -> "2"
List("a","c") -> "3"
https://stackoverflow.com/questions/47317040
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