第五部分习题 - 图1

    第五部分习题 - 图2

    1. package main
    3. import (
    4.     "fmt"
    5.     "math/rand"
    6.     "time"
    7. )
    9. type honeyBee struct {
    10.     name string
    11. }
    13. func (hb honeyBee) String() string {
    14.     return hb.name
    15. }
    17. func (hb honeyBee) move() string {
    18.     switch rand.Intn(2) {
    19.     case 0:
    20.         return "buzzes about"
    21.     default:
    22.         return "flies to infinity and beyond"
    23.     }
    24. }
    26. func (hb honeyBee) eat() string {
    27.     switch rand.Intn(2) {
    28.     case 0:
    29.         return "pollen"
    30.     default:
    31.         return "nectar"
    32.     }
    33. }
    35. type gopher struct {
    36.     name string
    37. }
    39. func (g gopher) String() string {
    40.     return g.name
    41. }
    43. func (g gopher) move() string {
    44.     switch rand.Intn(2) {
    45.     case 0:
    46.         return "scurries along the ground"
    47.     default:
    48.         return "burrows in the sand"
    49.     }
    50. }
    52. func (g gopher) eat() string {
    53.     switch rand.Intn(5) {
    54.     case 0:
    55.         return "carrot"
    56.     case 1:
    57.         return "lettuce"
    58.     case 2:
    59.         return "radish"
    60.     case 3:
    61.         return "corn"
    62.     default:
    63.         return "root"
    64.     }
    65. }
    67. type animal interface {
    68.     move() string
    69.     eat() string
    70. }
    72. func step(a animal) {
    73.     switch rand.Intn(2) {
    74.     case 0:
    75.         fmt.Printf("%v %v.\n", a, a.move())
    76.     default:
    77.         fmt.Printf("%v eats the %v.\n", a, a.eat())
    78.     }
    79. }
    81. const sunrise, sunset = 8, 18
    83. func main() {
    84.     rand.Seed(time.Now().UnixNano())
    86.     animals := []animal{
    87.         honeyBee{name: "Bzzz Lightyear"},
    88.         gopher{name: "Go gopher"},
    89.     }
    91.     var sol, hour int
    93.     for {
    94.         fmt.Printf("%2d:00 ", hour)
    95.         if hour < sunrise || hour >= sunset {
    96.             fmt.Println("The animals are sleeping.")
    97.         } else {
    98.             i := rand.Intn(len(animals))
    99.             step(animals[i])
    100.         }
    102.         time.Sleep(500 * time.Millisecond)
    104.         hour++
    105.         if hour >= 24 {
    106.             hour = 0
    107.             sol++
    108.             if sol >= 3 {
    109.                 break
    110.             }
    111.         }
    112.     }
    113. }