algo/di-yi-zhan-da78c/shou-ba-sh-48c1d/dai-quan-z-585d6/

[giscus[bot]]

algo/di-yi-zhan-da78c/shou-ba-sh-48c1d/dai-quan-z-585d6/

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https://labuladong.github.io/algo/di-yi-zhan-da78c/shou-ba-sh-48c1d/dai-quan-z-585d6/

[caoyiyang1105]

👍👍👍

[CZT0]

golang代码没翻译，我给个版本

type Solution struct {
    preSum []int
}


func Constructor(w []int) Solution {
    n:=len(w)
    preSum:=make([]int,n+1)
    for i:=0;i<n;i++{
        preSum[i+1]=preSum[i]+w[i]
    }
    return Solution{preSum:preSum}
}


func (this *Solution) PickIndex() int {
    n:=len(this.preSum)
    total := this.preSum[len(this.preSum)-1]
    random:=rand.Intn(total)+1
    index:=sort.Search(n,func(i int)bool {return this.preSum[i]>=random})
    return index-1

}

[BruceZZ1998]

总权重是7份，各自占1/7,2/7,3/7,1/7,应该是[0,7]的闭区间啊，为啥是【1，7】的闭区间，如果是[1,7]的闭区间岂不是说第一个数字被选到的概率为无限接近于0？