A Tour of Go Exercise: Fibonacci closure

44.go

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	f2, f1 := 0, 1
	return func() int {
		f := f2
		f2, f1 = f1, f+f1

		return f
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}

package main

import "fmt"

func fibonacci() func() uint64 {
	
	a := uint64(0)
	b := uint64(0)
	c := uint64(a + b)

	return func() uint64 {
		if c-a > c-b {
			c = c + (c - a)
			a = c - b
			return c
		} else if c-a < c-b {
			c = c + (c - b)
			b = c - a
			return c
		} else if c == c {
			a += 0
			b += 1
			c += 1
			return c
		}
		return c
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 1000; i++ {
		fmt.Println(f())
	}
}

package main

import "fmt"

func fibonacci() func() int {
	f := [10]int{0, 1}
	i := 0

	return func() int {
		last := i
		i++

		if last == 0 || last == 1 {
			return f[last]
		}

		f[last] = f[last-1] + f[last-2]

		return f[last]
	}
}

func main() {
	f := fibonacci()

	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}

package main

import "fmt"

func fibonacci() func() int {
	fib, temp, next := 0, 0, 1
	
	return func() int {
		fib = temp
		temp = next
		next = fib + temp
		return fib
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
	num := 0
	nextNum := 1
	advance := func () {
		temp := nextNum
		nextNum = num + nextNum
		num = temp
	}
	return func () int {
		defer advance()
		return num
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}

package main

import "fmt"

// fibonacci is a function that returns
// a function that returns an int.
func fibonacci() func() int {
f1 := 0
f2 := 1
reFunc := func() int {
f := f1
f1 = f2
f2 = f + f1
return f
}
return reFunc
}

func main() {
f := fibonacci()
for i := 0; i < 100; i++ {
fmt.Println(f())
}
}

package main

import "fmt"

func fibonacci() func() int {
	a, b := 1, 0
	return func() int {
		a, b = b, a + b
		return a
	}
}

func main() {
	f := fibonacci()
	for i := 0; i < 10; i++ {
		fmt.Println(f())
	}
}