package com.huc.WordCount

object WordCount1 {
  def main(args: Array[String]): Unit = {
    // 需求：将集合中出现的相同的单词，进行计数，取计数排名前三的结果
    val stringList = List("Hello Scala Hbase kafka", "Hello Scala Hbase", "Hello Scala", "Hello")

    // 步骤一：扁平化拆分成长字符串
    val strings = stringList.flatMap((s: String) => s.split(" "))
    val strings1 = stringList.flatMap(_.split(" "))
    println(strings)

    // 步骤二：将相同的单词分组到一起
    strings.groupBy((s: String) => s)
    val map = strings.groupBy(s => s)
    println(map)

    // 步骤三：转换数据格式为  (单词，次数)
    val map1 = map.map((tuple: (String, List[String])) => (tuple._1, tuple._2.size))
    val map2 = map.map(tuple => (tuple._1, tuple._2.size))
    println(map1)

    val map3 = map.mapValues(_.size)
    println(map3)

    // 步骤四：排序
    val tuples = map3.toList.sortBy((tuple: (String, Int)) => tuple._2)
    println(tuples)

    val tuples1 = map3.toList.sortBy((test: (String, Int)) => test._2)(Ordering[Int].reverse)
    val tuples2 = map3.toList.sortBy(_._2)(Ordering[Int].reverse)
    println(tuples1)

    val tuples3 = map3.toList.sortWith((left: (String, Int), right: (String, Int)) => left._2 > right._2)
    val tuples4 = map3.toList.sortWith(_._2 > _._2)
    println(tuples3)

    // 步骤五：取top3
    println(tuples4.take(3))

    // 熟练的写法
    val tuples5 = stringList.flatMap(_.split(" "))
      .groupBy(s => s)
      .map(tuple => (tuple._1, tuple._2.size))
      .toList.sortWith(_._2 > _._2)
      .take(3)
    println(tuples5)


  }
}