Merge pull request #53 from khanhhuynguyenvu/new_branch

fix(travis): travis automation testing

Author: StepfenShawn

.travis.yml

@@ -1,5 +1,9 @@
+dist: trusty
+
 language: scala
+
 scala:
-  - 2.9.3
-  - 2.10.6
-  - 2.11.11
+  - 2.13.1
+
+jdk:
+  - openjdk8

src/main/scala/Search/BinarySearch.scala

@@ -44,4 +44,33 @@ object BinarySearch {
 
     SearchImpl(fromIndex, toIndex - 1)
   }
+
+  /**
+    *
+    * @param arr  - a sequence of integers
+    * @param elem - a integer to search for in the @args
+    * @return
+    */
+  def lowerBound(arr: List[Int], elem: Int): Int = {
+    lowerBound(arr, elem, 0, arr.length - 1)
+  }
+
+  /**
+    *
+    * @param arr  - a sequence of integers
+    * @param elem - a integer to search for in the @args
+    * @param lo   - lowest value index
+    * @param hi   - highest value index
+    * @return
+    */
+  def lowerBound(arr: List[Int], elem: Int, lo: Int, hi: Int): Int = {
+    if (lo == hi) lo
+    else {
+      val m: Int = lo + (hi - lo) / 2
+      arr(m) match {
+        case mv if (mv < elem) => lowerBound(arr, elem, m + 1, hi)
+        case mv if (mv >= elem) => lowerBound(arr, elem, lo, m)
+      }
+    }
+  }
 }

src/test/scala/Mathematics/FindMaxSpec.scala

@@ -4,11 +4,11 @@ import org.scalatest.FlatSpec
 
 class FindMaxSpec extends FlatSpec {
 
-  it should "output the correct Integer as a result from the list of elements" in {
+  "FindMaxSpec 1" should "output the correct Integer as a result from the list of elements" in {
     assert(FindMax.findMax(List(-1000, -1, 999, 72, 65, -56, -767)) === 999)
   }
 
-  it should "output the correct Integer as a result from the list of elements" in {
+  "FindMaxSpec 2" should "output the correct Integer as a result from the list of elements" in {
     assert(FindMax.findMax(List(121, 221, 3, 4112)) === 4112)
   }
 

src/test/scala/Mathematics/FindMinSpec.scala

@@ -4,11 +4,11 @@ import org.scalatest.FlatSpec
 
 class FindMinSpec extends FlatSpec {
 
-  it should "output the correct Integer as a result from the list of elements" in {
+  "FindMinSpec 1" should "output the correct Integer as a result from the list of elements" in {
     assert(FindMin.findMin(List(-1000, -1, 999, 72, 65, -56, -767)) === -1000)
   }
-
-  it should "output the correct Integer as a result from the list of elements" in {
+1
+  "FindMinSpec 2" should "output the correct Integer as a result from the list of elements" in {
     assert(FindMin.findMin(List(121, 221, 3, 4112)) === 3)
   }
 

src/test/scala/Search/BinarySearchSpec.scala

@@ -32,4 +32,16 @@ class BinarySearchSpec extends FlatSpec {
     assert(BinarySearch.binarySearch(l, 7, 0, 4) === -1)
     assert(BinarySearch.binarySearch(l, 7, 1, 3) === -1)
   }
+
+  "A lower Bound" should "return the index of first appearance element" in {
+    val m = List(1, 3, 5, 5, 5, 9, 9, 13, 13, 20)
+    assert(BinarySearch.lowerBound(m, 5) === 2)
+    assert(BinarySearch.lowerBound(m, 9) === 5)
+  }
+  "A lower bound" should "return the index of number larger than an element and which is smallest" in {
+    val m = List(1, 3, 5, 5, 5, 9, 9, 13, 13, 20)
+    assert(BinarySearch.lowerBound(m, 4) === 2)
+    assert(BinarySearch.lowerBound(m, 8) === 5)
+    assert(BinarySearch.lowerBound(m, 10) === 7)
+  }
 }