Add some docs, tests and cleanup the code a bit

geektimus · geektimus · commit 9651af6ad7da · 2019-08-29T18:15:20.000-05:00
diff --git a/README.md b/README.md
@@ -128,6 +128,23 @@ of three print “Fizz” instead of the number and for the multiples of five pr
 This is a basic problem where we need to find if a number is present on the
 given array.
 
+#### Basic word count problem but without using REGEX expressions.
+
+Write a function which returns the number of words in a given string - without using REGEX expressions
+
+```
+given "disco1 hero2" or
+      "  disco1  hero2" or
+      "disco1  hero2  " or
+      "  disco1  hero2  "
+then the word count should be 2, the solution should ignore the spaces.
+```
+
+#### Find the last index of a slice on a given array
+
+Write a function which prints the index of the last occurrence of the entire sequence within a given array 
+WITHOUT using inbuilt **sliding**, **lastIndexOf** and **lastIndexOfSlice** functions.
+
 ## Useful commands
 
 ### Enable scala style check on compile
diff --git a/src/main/scala/com/codingmaniacs/others/CollectionChallenges.scala b/src/main/scala/com/codingmaniacs/others/CollectionChallenges.scala
@@ -9,7 +9,7 @@ object CollectionChallenges {
       (a, s) match {
         case (List(), List()) => List()
         case (ls, List()) => ls
-        case (ina :+ enda, ins :+ ends) if enda == ends => lastIndexSeen(ina, ins)
+        case (ina :+ endA, ins :+ endS) if endA == endS => lastIndexSeen(ina, ins)
         case (ina :+ _, _) => lastIndexSeen(ina, s)
       }
     }
diff --git a/src/main/scala/com/codingmaniacs/others/StringChallenges.scala b/src/main/scala/com/codingmaniacs/others/StringChallenges.scala
@@ -14,9 +14,15 @@ object StringChallenges {
     * @return Reverse representation of the string
     */
   def flip(str: String): String = {
-    str.foldRight("") ((el, acc) => acc + el)
+    str.foldRight("")((el, acc) => acc + el)
   }
 
+  /**
+    * Given a string it returns the number of words contained in the string
+    *
+    * @param str String
+    * @return Number of words found on the string using split method
+    */
   def wordCountWithSplit(str: String): Int = {
     str
       .trim
@@ -25,23 +31,28 @@ object StringChallenges {
       .count(w => !w.equals(""))
   }
 
+  /**
+    * Given a string it returns the number of words contained in the string
+    *
+    * @param str String
+    * @return Number of words found on the string using recursion
+    */
   def wordCountWithRec(str: String): Int = {
 
     @tailrec
     def wordCountRec(charSeq: List[Char], spaces: Int): Int = {
       charSeq match {
         case Nil => spaces + 1
-        case h :: th :: tail if h == 32 && th == 32 => {
+        case h :: th :: tail if h == 32 && th == 32 =>
           wordCountRec(th :: tail, spaces)
-        }
-        case h :: th :: tail if h == 32 && th != 32 => {
+        case h :: th :: tail if h == 32 && th != 32 =>
           wordCountRec(tail, spaces + 1)
-        }
         case _ :: tail => {
           wordCountRec(tail, spaces)
         }
       }
     }
+
     str match {
       case "" => 0
       case _ =>
diff --git a/src/test/scala/com/codingmaniacs/others/CollectionChallengesSpec.scala b/src/test/scala/com/codingmaniacs/others/CollectionChallengesSpec.scala
@@ -44,5 +44,15 @@ class CollectionChallengesSpec extends Specification {
       val reverse = CollectionChallenges.lastIndexOfSlice(s, slice)
       reverse mustEqual expected
     }
+
+    "find the last index of a big slice on an array" in {
+      // scalastyle:off magic.number
+      val s =  Array(7,2,3,4,6,9,3,4,6,21,8)
+      val slice =  Array(3,4,6,9)
+      // scalastyle:on magic.number
+      val expected = 2
+      val reverse = CollectionChallenges.lastIndexOfSlice(s, slice)
+      reverse mustEqual expected
+    }
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@ object CollectionChallenges {`
`9`	`9`	`(a, s) match {`
`10`	`10`	`case (List(), List()) => List()`
`11`	`11`	`case (ls, List()) => ls`
`12`		`- case (ina :+ enda, ins :+ ends) if enda == ends => lastIndexSeen(ina, ins)`
	`12`	`+ case (ina :+ endA, ins :+ endS) if endA == endS => lastIndexSeen(ina, ins)`
`13`	`13`	`case (ina :+ _, _) => lastIndexSeen(ina, s)`
`14`	`14`	`}`
`15`	`15`	`}`
Original file line number	Diff line number	Diff line change
`@@ -44,5 +44,15 @@ class CollectionChallengesSpec extends Specification {`
`44`	`44`	`val reverse = CollectionChallenges.lastIndexOfSlice(s, slice)`
`45`	`45`	`reverse mustEqual expected`
`46`	`46`	`}`
	`47`	`+`
	`48`	`+ "find the last index of a big slice on an array" in {`
	`49`	`+ // scalastyle:off magic.number`
	`50`	`+ val s = Array(7,2,3,4,6,9,3,4,6,21,8)`
	`51`	`+ val slice = Array(3,4,6,9)`
	`52`	`+ // scalastyle:on magic.number`
	`53`	`+ val expected = 2`
	`54`	`+ val reverse = CollectionChallenges.lastIndexOfSlice(s, slice)`
	`55`	`+ reverse mustEqual expected`
	`56`	`+ }`
`47`	`57`	`}`
`48`	`58`	`}`