D**u
发帖数: 204 | 1 【 以下文字转载自 Mathematics 讨论区 】
发信人: DuGu (火工头陀), 信区: Mathematics
标 题: election problem
发信站: BBS 未名空间站 (Wed Aug 8 19:17:51 2007)
Two candidates (R and L) are for the 2008 election. In the election, voters
are in a single line and are going to vote one by one. After each voter
makes the vote, the other voters immediately knows who he/she voted for.
Voters tend to stay with the "winner's side", if at the moment the
candidates have x and y votes respectively, the voter will vote R with
probability x/ | D**u
发帖数: 204 | 2 Answer is Beta distribution
f(t; x0,y0) = 1/Beta(x0,y0) * (1-t)^(x0-1) * t^(y0-1)
= gamma(x0+y0)/(gamma(x0) * gamma(y0)) * (1-t)^(x0-1) * t^(y0-1).
See http://mitbbs.com/article_t/Mathematics/24392447.html
for more detail.
voters
【在 D**u 的大作中提到】
: 【 以下文字转载自 Mathematics 讨论区 】
: 发信人: DuGu (火工头陀), 信区: Mathematics
: 标 题: election problem
: 发信站: BBS 未名空间站 (Wed Aug 8 19:17:51 2007)
: Two candidates (R and L) are for the 2008 election. In the election, voters
: are in a single line and are going to vote one by one. After each voter
: makes the vote, the other voters immediately knows who he/she voted for.
: Voters tend to stay with the "winner's side", if at the moment the
: candidates have x and y votes respectively, the voter will vote R with
: probability x/
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