Arrays 如何跟踪数组中的索引

在scala中对

数组

使用

滑动

函数时，根据原始数组跟踪滑动子数组索引的正确方法是什么

// Initialize some data
val bigArray = List(2, 3, 4, 2, 3, 6, 8, 4, 5).toArray
val n:Int = 5

// Slide through the big array
for (smallArray <- bigArray.sliding(n)) {
  val thirdValue:Int = smallArray(3)
  val k = (bigArray zip smallArray) lastIndexWhere { case (x, y) => x < y }
  if (bigArray(k+1) >= thirdValue) {
    println(bigArray.toList.toString + 
      " has "
      + bigArray(k+1)
      + " >= " 
      + thirdValue 
      + " in "
      + smallArray.toList.toString
      + " at index "
      + k+1)
  }

我需要

List(2, 3, 4, 2, 3, 6, 8, 4, 5) has 6 >= 2 in List(2, 3, 4, 2, 3) at index 5
List(2, 3, 4, 2, 3, 6, 8, 4, 5) has 8 >= 3 in List(3, 4, 2, 3, 6) at index 6

更新

---

我无法让

map

使用

tuple2（Int，Int）

，该tuple2（Int，Int）来自公认答案中的

head

，但是提到

zipWithIndex

让我达到了目的，所以我接受了有用的答案。这就是我的结局：

for (zipArray <- bigArray.slice(0, bigArray.length - 1).zipWithIndex.sliding(n)) {
  val j = zipArray.head._2
  val k = zipArray.last._2
  val smallArray = bigArray.slice(j, k)
  val thirdValue:Int = smallArray(3)
  if (bigArray(k+1) >= thirdValue) {
    println(bigArray.toList.toString +
      " has "
      + bigArray(k+1)
      + " >= "
      + thirdValue
      + " in "
      + smallArray.toList.toString
      + " at index "
      + (k+1) )
  }
}

---

您可以在滑动之前使用zipWithIndex：

for (smallArrayWithIndex <- bigArray.zipWithIndex.sliding(n)) {
    val startingIndex = smallArrayWithIndex.head.map { case (_, index) => index }
    val smallArray = smallArrayWithIndex.map { case (e, _) => e }
    println("smallArray starts at index " + index + " and contains " + smallArray)
}

for（smallArrayWithIndex索引}
val smallArray=smallArrayWithIndex.map{case（e，)）=>e}
println（“smallArray从索引“+index+”开始，包含“+smallArray”）
}

您可以在

滑动之前使用
zipWithIndex
：

for (smallArrayWithIndex <- bigArray.zipWithIndex.sliding(n)) {
    val startingIndex = smallArrayWithIndex.head.map { case (_, index) => index }
    val smallArray = smallArrayWithIndex.map { case (e, _) => e }
    println("smallArray starts at index " + index + " and contains " + smallArray)
}

for（smallArrayWithIndex索引}
val smallArray=smallArrayWithIndex.map{case（e，)）=>e}
println（“smallArray从索引“+index+”开始，包含“+smallArray”）
}
谢谢。我需要做什么才能让标准的
映射
作用于
smallArrayWithIndex.head
即
（Int，Int）
。我无法得到
map
来解决问题，但您对
zipWithIndex
的帮助最终让我达到了目的。谢谢。谢谢。谢谢。我需要做些什么才能让标准
map
作用于
smallArrayWithIndex.head
，即
（Int，Int）
。我无法得到
map
来解决问题，但您对
zipWithIndex
的帮助最终让我达到了目的。谢谢。
List(2, 3, 4, 2, 3, 6, 8, 4, 5) has 6 >= 2 in List(2, 3, 4, 2) at index 5
List(2, 3, 4, 2, 3, 6, 8, 4, 5) has 8 >= 3 in List(3, 4, 2, 3) at index 6

for (smallArrayWithIndex <- bigArray.zipWithIndex.sliding(n)) {
    val startingIndex = smallArrayWithIndex.head.map { case (_, index) => index }
    val smallArray = smallArrayWithIndex.map { case (e, _) => e }
    println("smallArray starts at index " + index + " and contains " + smallArray)
}