feat: binary search

Author: vitorsavian

go/pkg/array/search.go

@@ -1,5 +1,23 @@
 package array
 
-func binarySearch(arr []int) {
+func BinarySearch(arr []int, item int) int {
+	low := 0
+	high := len(arr) - 1
 
+	for high >= low {
+		guess := (high + low) / 2
+
+		if guess == item {
+			return guess
+		}
+
+		if guess > item {
+			high = guess - 1
+		} else {
+			low = guess + 1
+		}
+
+	}
+
+	return 0
 }

go/pkg/array/search_test.go

@@ -0,0 +1,25 @@
+package array_test
+
+import (
+	"testing"
+
+	"github.com/vitorsavian/algo/pkg/array"
+)
+
+func TestBinarySearch(t *testing.T) {
+	arr := make([]int, 100)
+
+	want := 27
+
+	n := 1
+	for n <= 100 {
+		arr[n-1] = n
+		n++
+	}
+
+	result := array.BinarySearch(arr, want)
+
+	if want != result {
+		t.Fatalf("Unable to get binary search right: %d", result)
+	}
+}

go/pkg/array/sort.go

@@ -1 +1,6 @@
 package array
+
+func InsertSort(arr []int) []int {
+	var stuff []int
+	return stuff
+}