抽卡、抽奖、掉落库 drawcard 、lottery
type Interface interface {
// Len is the number of elements in the collection.
Len() int
// Weight returns weight of the elements at index i.
Weight(i int) int
}
Draw returns the index of elements
func Draw(data Interface, count int, repeated bool) []int
RandInt returns as an int, a non-negative pseudo-random number in [min,max]
func RandInt(min, max int) int
RandIntWave returns as an int, a number in [num - wave, num + wave]
func RandIntWave(num, wave int) int
RandIntAbs like RandIntWave. but a number in [1, num + wave], if num - wave < 0.
func RandIntAbs(num, wave int) int
type Slice struct {
items []*Item
}
type Item struct {
ID string
Weight int // 权重
Count int // 产出数量
Wave int // 产出数量的波动大小
}
func (s *Slice) Len() int {
return len(s.items)
}
func (s *Slice) Weight(i int) int {
return s.items[i].Weight
}
func (s *Slice) Print(ret []int) {
for _, idx := range ret {
item := s.items[idx]
count := RandIntAbs(item.Count, item.Wave)
fmt.Printf("[ID:%s, Count:%d]", item.ID, count)
}
fmt.Println()
}
func init() {
rand.Seed(time.Now().Unix())
}
func TestDraw(t *testing.T) {
s := &Slice{items: []*Item{
{ID: "11", Weight: 10, Wave: 2, Count: 10}, // 0.1
{ID: "22", Weight: 15, Wave: 5, Count: 6}, // 0.15
{ID: "33", Weight: 20, Wave: 6, Count: 3}, // 0.2
{ID: "44", Weight: 25, Wave: 4, Count: 5}, // 0.25
{ID: "55", Weight: 30, Wave: 0, Count: 3}, // 0.3
}}
// 允许重复
result := Draw(s, 4, true)
s.Print(result)
// 不允许重复
result = Draw(s, 4, false)
s.Print(result)
}
// out
[ID:55, Count:3][ID:33, Count:5][ID:44, Count:5][ID:44, Count:3]
[ID:55, Count:3][ID:22, Count:3][ID:44, Count:5][ID:33, Count:6]