Question

我有以下数组：

Array(book, chalk, book, eraser),  
Array(book, chalk, book, pen),  
Array(book, chalk, book, pencil),  
Array(book, chalk, chalk, eraser),  
Array(book, chalk, chalk, pen),  
Array(book, chalk, chalk, pencil),  
Array(book, chalk, eraser, pen)
Array(book, chalk, eraser, pencil),  
Array(book, chalk, pen, pencil)
Array(book, eraser, book, pen),  
Array(book, eraser, book, pencil),  
Array(book, eraser, chalk, eraser)

我想删除具有不同字符串的数组。例如：Array(book,chalk,eraser,pencil)需要删除。

我该怎么办？

Answer 1

你可以简单地使用：

val arr = Array(Array("book","chalk", "pencil","eraser"),Array("book","chalk", "book","pen"),Array("book","chalk", "book","pencil"),Array("book","chalk", "chalk","eraser"),Array("book","chalk", "chalk","pen"))

arr.filter(x => x.length != x.toSet.size)

Answer 2

而不是不同，你可以使用简单的自定义函数，它会更有效率，因为它不应该遍历整个数组，如果复制是在数组的开头：

import scala.collection.mutable

def hasDuplicate[T](arr: Array[T]): Boolean = {
  val seen = mutable.HashSet[T]()
  var seenBefore = false
  var i = 0
  while (!seenBefore && i < arr.length ) {
    val v = arr(i)
    seenBefore = seen.contains(v)
    seen += v
    i += 1
  }
  seenBefore
}

val input = Array(Array("book","chalk", "pencil","eraser"),Array("book","chalk", "book","pen"),Array("book","chalk", "book","pencil"),Array("book","chalk", "chalk","eraser"),Array("book","chalk", "chalk","pen"))
input.filterNot(hasDuplicate)

如何检查每行数据集中的多个String？

2 个答案: