Lab 2: Bubble Sort

02_bubble/nicholsk/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+var out io.Writer = os.Stdout
+
+func main() {
+	fmt.Fprintln(out, bubble([]int{3, 2, 1, 5}))
+}
+
+func bubble(s []int) []int {
+
+	// track whether the sort is complete
+	sorted := false
+
+	// make a slice copy to perform sort on
+	sCopy := s
+
+	for !sorted {
+
+		// track whether any swaps took place in current iteration
+		swaps := false
+
+		// iterate every index in the list, starting at index 1
+		for i := 1; i < len(s); i++ {
+
+			// compare element to previous
+			if sCopy[i-1] > sCopy[i] {
+
+				// if less than previous then swap elements
+				sCopy[i], sCopy[i-1] = sCopy[i-1], sCopy[i]
+				swaps = true
+			}
+
+		}
+
+		// an iteration with no swaps indicates the array is sorted
+		if !swaps {
+			sorted = true
+		}
+	}
+
+	return sCopy
+}

02_bubble/nicholsk/main_test.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bytes"
+	"math/rand"
+	"sort"
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBubbleSortMain(t *testing.T) {
+	var buf bytes.Buffer
+	out = &buf
+
+	main()
+
+	expected := strconv.Quote("[1 2 3 5]\n")
+	actual := strconv.Quote(buf.String())
+
+	if expected != actual {
+		t.Errorf("Unexpected output in main()")
+	}
+}
+
+func TestBubbleWithSmallSlice(t *testing.T) {
+	a := assert.New(t)
+
+	sorted := bubble([]int{2, 1})
+	expected := []int{1, 2}
+
+	a.Equal(expected, sorted)
+}
+
+func TestBubbleWithLargeSlice(t *testing.T) {
+	a := assert.New(t)
+
+	expected := make([]int, 100)
+	for i := range expected {
+		expected[i] = rand.Intn(1000)
+	}
+
+	sorted := bubble(expected)
+	sort.Ints(expected)
+
+	a.Equal(expected, sorted)
+}
+
+func TestBubbleWithSmallSliceIncludingNegativeInts(t *testing.T) {
+	a := assert.New(t)
+
+	sorted := bubble([]int{1, -2, -3})
+	expected := []int{-3, -2, 1}
+
+	a.Equal(expected, sorted)
+}