Add task 4 in go

Author: Holger Lösken

src/go/t4/s1.go

@@ -0,0 +1,36 @@
+package main
+
+import "fmt"
+
+func JumpOutOfArray(numbers []int) int {
+	sum := 0
+	jumps := 0
+
+	for index, number := range numbers {
+		sum += numbers[sum]
+
+		// Jump out of array at the start of the array
+		if (index + number) < 0 {
+			jumps++
+			break
+		}
+
+		jumps++
+
+		// Jump out of array at the end of the array
+		if sum > len(numbers) {
+			break
+		}
+
+		// End of array but do not jump out
+		if (index + 1) == len(numbers) {
+			jumps = -1
+		}
+	}
+
+	return jumps
+}
+
+func main() {
+	fmt.Println(JumpOutOfArray([]int { 2, 3, -1, 1, 6 }))
+}

src/go/t4/s1_test.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestJumpOutOfArray(t *testing.T) {
+	type test struct {
+		input []int
+		want int
+	}
+
+	tests := []test{
+		{input: []int {2, 3, -1, 1, 6}, want: 4},
+		{input: []int {-1, 3, -1, 1, 6}, want: 1},
+		{input: []int {1, 2, 1, 1, 1, 0}, want: -1},
+	}
+
+	for _, tc := range tests {
+		got := JumpOutOfArray(tc.input)
+		if !reflect.DeepEqual(tc.want, got) {
+			t.Fatalf("input: %v, expected: %v, got: %v", tc.input, tc.want, got)
+		}
+	}
+}