main.go

package main

import (
	"context"
	"fmt"
	"time"
)

func main() {
	
	 for i := 0; i <= 10; i++ {
	 	index, value := fibonacciIndex(i)
	 	fmt.Printf("Index: %d, Value: %d \n", index, value)
	 }

	index, value := fibonacciValue(3)
	fmt.Printf("\n Index: %d, Value: %d \n", index, value)
}

//fibonacciValue pass value and returns index and value of the next element of fibonacci series
func fibonacciValue(val int) (index, value int) {
	i := 0
	t1 := 0
	t2 := 1
	nextTerm := 0

	if val == 0 {
		return 1, 1
	}

	for i = 0; nextTerm < val+1; i++ {
		if i == 0 {
			fmt.Print(" ", t1)
			continue
		}
		if i == 1 {
			fmt.Print(" ", t2)
			continue
		}
		nextTerm = t1 + t2
		t1 = t2
		t2 = nextTerm
		fmt.Print(" ", nextTerm)
	}
	return i - 1, nextTerm
}

//fibonacciIndex pass index and returns index and value of the next element of fibonacci series
func fibonacciIndex(indx int) (index, value int) {
	i := 0
	t1 := 0
	t2 := 1
	nextTerm := 0

	for i = 0; i <= indx; i++ {
		if i == 0 {
			continue
		}

		nextTerm = t1 + t2
		if i == 1 {
			continue
		}

		t1 = t2
		t2 = nextTerm
	}
	return indx, nextTerm
}