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284
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import CW7b._
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263
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2 |
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284
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3 |
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// first test
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263
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5 |
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284
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6 |
val ls1_urban = List(("1", "a"), ("2", "a"), ("1", "c"), ("2", "a"), ("1", "c"))
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val m_urban = groupById(ls1_urban, Map())
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263
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9 |
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assert(m_urban.getOrElse("1", Nil).count(_ == "c") == 2)
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assert(m_urban.getOrElse("1", Nil).count(_ == "a") == 1)
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assert(m_urban.getOrElse("2", Nil) == List("a", "a"))
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284
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// second test
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def urban_gb(ratings: List[(String, String)]) =
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ratings.groupBy(_._1).view.mapValues(_.map(_._2).toSet).toMap
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def urban_gb2(ratings: List[(String, String)]) =
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ratings.groupBy(_._1).view.mapValues(_.map(_._2)).toMap
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def urban_ck(ratings: List[(String, String)]) =
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urban_gb(ratings) == groupById(ratings, Map()).view.mapValues(_.toSet).toMap
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val ls2_urban = List(("1", "a"), ("1", "b"), ("2", "x"), ("3", "a"), ("2", "y"), ("3", "c"))
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assert(urban_ck(ls2_urban))
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// thrird test
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val ls3_urban = (1 to 1000).map(_.toString).toList
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val ls4_urban = ls3_urban zip ls3_urban.tail
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val ls5_urban = ls4_urban ::: ls4_urban.reverse
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assert(urban_ck(ls5_urban))
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384
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38 |
// fourth test !!!
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284
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/*
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384
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val ls6_urban = (10 to 500 by 10).map(_.toString).toList
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val ls7_urban = ls6_urban zip ls6_urban.tail
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val ls8_urban = ls7_urban ::: ls7_urban.reverse
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284
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45 |
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384
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assert(urban_ck(ls8_urban))
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284
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*/
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