遞迴的經典範例,費波那契數列.

// hello29
package main

import (
	"fmt"
)

func main() {
	result := 0
	for i := 0; i <= 15; i++ {
		result = fibonacci(i)
		fmt.Printf("fibonacci(%2d) -> %3d\n", i, result)
	}
}

func fibonacci(n int) (rtn int) {
	if n <= 1 {
		rtn = 1
	} else {
		rtn = fibonacci(n-1) + fibonacci(n-2)
	}
	return
}

執行結果:

$ ./hello29 
fibonacci( 0) ->   1
fibonacci( 1) ->   1
fibonacci( 2) ->   2
fibonacci( 3) ->   3
fibonacci( 4) ->   5
fibonacci( 5) ->   8
fibonacci( 6) ->  13
fibonacci( 7) ->  21
fibonacci( 8) ->  34
fibonacci( 9) ->  55
fibonacci(10) ->  89
fibonacci(11) -> 144
fibonacci(12) -> 233
fibonacci(13) -> 377
fibonacci(14) -> 610
fibonacci(15) -> 987