enh(Go): binary-search (#273)

algorithms/Go/searching/binary-search.go

@@ -6,32 +6,39 @@ import (
 	"time"
 )
 
-func binarySearch(arr []int, elem int) {
+func binarySearch(arr []int, elem int) (int, bool) {
 	var (
 		start = 0
 		end   = len(arr) - 1
 	)
 
-	fmt.Printf("Array: %v\nNumber to be searched: %v\n", arr, elem)
-
 	for start <= end {
 		mid := start + (end-start)/2
 		if elem == arr[mid] {
-			fmt.Printf("Number found at index %v", mid)
-			return
+
+			return mid, true
 		} else if elem < arr[mid] {
 			end = mid - 1
 		} else {
 			start = mid + 1
 		}
 	}
+	return -1, false
 
-	fmt.Printf("Number not found!\n")
 }
 
 func RunBinarySearch() {
 	rand.Seed(time.Now().UnixNano())
 	arr := []int{1, 2, 4, 7, 8, 9, 12, 14, 17, 18, 20, 22, 23, 24, 26, 27, 29}
 	elem := rand.Intn(20)
-	binarySearch(arr, elem)
+
+	fmt.Printf("Array: %v\nNumber to be searched: %v\n", arr, elem)
+	index, found := binarySearch(arr, elem)
+	if !found {
+		fmt.Printf("Number not found!\n")
+	} else {
+		fmt.Printf("Number found at index %v", index)
+	}
+
 }
+