Binary Search in Go

search.go

package search

func BinarySearch(arr []int, target int) int {
	start := 0
	end := len(arr) - 1
	for start <= end {
		midPos := (start + end) / 2
		if target < arr[midPos] {
			end = midPos - 1
		} else if target > arr[midPos] {
			start = midPos + 1
		} else {
			return midPos
		}
	}
	return -1
}

search_test.go

package search

import (
	"testing"
)

func TestBinarySearch(t *testing.T) {
	nums := []int{5, 9, 23, 245, 342, 900, 1003, 2000}
	tables := []struct {
		target   int
		expected int
	}{
		{5, 0},
		{2000, 7},
		{342, 4},
		{9, 1},
		{1000, -1},
	}

	for _, table := range tables {
		actual := BinarySearch(nums, table.target)
		if actual != table.expected {
			t.Errorf("Found is wrong, got: %d, want: %d.", actual,
				table.expected)
		}

	}
}