抽奖-随机加权算法

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package lottery   import (     "fmt"     "math/rand"     "sort"     "time" )   type Lottery struct { }   func NewLottery() *Lottery {     return &Lottery{} }   type Prize struct {     Name   string     Stock  int     Weight int //权重 }   // SortPrizes 按权重生序 func (l *Lottery) SortPrizes(prizes []Prize) {     sort.Slice(prizes, func(i, j int) bool {         return prizes[i].Weight < prizes[j].Weight     }) }   // CreateWeightRanges 创建权重区间 func (l *Lottery) CreateWeightRanges(prizeList []Prize) []int {     var weightRanges []int     totalWeight := 0     for _, item := range prizeList {         totalWeight = item.Weight + totalWeight         weightRanges = append(weightRanges, totalWeight)     }     return weightRanges }   func (l *Lottery) DrawPrize(prizeList []Prize, weightRanges []int) string {       //生成一个随机数     //播种     rand.Seed(time.Now().UnixNano())     randNum := rand.Intn(weightRanges[len(weightRanges)-1])     fmt.Println("随机数=", randNum)     fmt.Println("权重slice=", weightRanges)     for i, rangeNum := range weightRanges {         if randNum < rangeNum {             return prizeList[i].Name         }     }     return "" }   func TestDraw() {     // 定义奖品信息及库存     prizes := []Prize{         {"一等奖 iPhone 16 Max", 1, 1},         {"二等奖 iPad", 1, 1},         {"三等奖 苹果耳机", 1, 1},         {"四等奖 红米手机", 5, 4},         {"五等奖 苹果手机充电器", 10, 5},         {"六等奖 红牛", 20, 8},         {"七等奖 矿泉水", 20, 10},         {"八等奖 微信10元立减金", 30, 12},         {"九等奖 微信3元立减金", 30, 14},     }     p := NewLottery()     p.SortPrizes(prizes)     weightRanges := p.CreateWeightRanges(prizes)     for i := 0; i < 1; i++ {         result := p.DrawPrize(prizes, weightRanges)         fmt.Printf("抽中奖品:%s\n", result)     } }

　　权重值约大，中奖概率越大。逻辑是控制随机数落到每个奖品的范围概率。