first commit

Author: mxssl

README.md

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+# Fibonacci sequence
+
+Fibonacci sequence implementation in Go (Golang).
+
+`Time complexity: O(n)`
+
+`Space complexity: O(1)`
+
+```Bash
+$ go test -v ./...
+=== RUN   TestCase1
+--- PASS: TestCase1 (0.00s)
+=== RUN   TestCase2
+--- PASS: TestCase2 (0.00s)
+PASS
+ok      github.com/mxssl/FibonacciGolang        0.005s
+```

main.go

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+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(getNthFib(6))
+}
+
+func getNthFib(n int) int {
+	lastTwo := []int{0, 1}
+	counter := 3
+	for counter <= n {
+		nextFib := lastTwo[0] + lastTwo[1]
+		lastTwo = []int{lastTwo[1], nextFib}
+		counter++
+	}
+	if n > 1 {
+		return lastTwo[1]
+	}
+	return lastTwo[0]
+}

main_test.go

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+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCase1(t *testing.T) {
+	expected := 0
+	output := getNthFib(1)
+	if !reflect.DeepEqual(output, expected) {
+		t.Fail()
+	}
+}
+
+func TestCase2(t *testing.T) {
+	expected := 1597
+	output := getNthFib(18)
+	if !reflect.DeepEqual(output, expected) {
+		t.Fail()
+	}
+}