Submissions to the backend code challenge 2018

solutions.py

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+#!/ysr/bin/env python2
+
+# 1. All primes from 0 to n
+def allPrimesToN(n):
+    """ Assumes input is an whole number n.
+        Returns a list of integers which are prime (n is included if it is prime) or an empty list if no prime numbers exist between 0 and n.
+    """
+    res = [] # results kept here
+    l = [True for i in range(n + 1)] # initialize primal
+    l[0] = l[1] = False
+    for i in range(2, n):
+        # Check all multiples of i as non prime
+        for j in range(2 * i, n + 1, i):
+            l[j] = False
+    for i in range(len(l)):
+        if l[i]:
+            res += [i] # Add to list if prime
+    return res
+
+
+# 2. All factorials from 0 to n
+def allFactToN(n):
+    """ Assumes input is a whole number n.
+        Returns a list of all factorials of the numbers 0 through n (inclusive)
+    """
+    if n == 0: # Base case: if n is zero return a list with only 1 as its element
+        return [1]
+    ret = allFactToN(n - 1)
+    # multiply the last element of ret with n and append it onto the ret
+    return ret + [ret[-1] * n]

solutions.scala

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+import scala.util.matching.Regex
+// 3. Pattern matching
+
+def typeMatching(list: List[Any]) = list match {
+   case Nil => "Empty list; No types"
+   case (head:String) :: _ => "A string list"
+   case (head:Int) :: _ => "An integer list"
+   case (head:Float) :: _ => "A float list"
+   case _ => "Other type of list"
+}
+
+// println(typeMatching(List("a", "a"))) // Outputs A string list
+// println(typeMatching(List(1.5.toFloat, 2.5.toFloat))) // Outputs A float list
+// println(typeMatching(List(1, 2))) // Outputs An integer list
+
+
+// 4. Regex matching
+def regexMatch(str: String) : Option[String] = {
+  val numPattern = new Regex("[0-9]+")
+  val match1 = numPattern.findFirstIn(str)
+  return match1
+}
+
+// println(regexMatch("7th floor Galana plaza, Kilimani")) // Outputs Some(7)
+
+
+// 5. Case class Person
+case class Person(name: String, age:Int) {
+  require(age > 0)
+}
+
+
+// new Person("Nathnael", 0) // Throws IllegalArgumentException