当前你的浏览器版本过低,网站已在兼容模式下运行,兼容模式仅提供最小功能支持,网站样式可能显示不正常。
请尽快升级浏览器以体验网站在线编辑、在线运行等功能。

建议使用的浏览器:

谷歌Chrome 火狐Firefox Opera浏览器 微软Edge浏览器 QQ浏览器 360浏览器 傲游浏览器

4987:Little Pony and Dice

题目描述
Twilight Sparkle was playing Ludo with her friends Rainbow Dash, Apple Jack and Flutter Shy. But she kept losing. Having returned to the castle, Twilight Sparkle became interested in the dice that were used in the game.

The dice has m faces: the first face of the dice contains a dot, the second one contains two dots, and so on, the m-th face contains m dots. Twilight Sparkle is sure that when the dice is tossed, each face appears with same probability. Also she knows that each toss is independent from others.

There is n + 1 cells in total, number from 0 to n, Twilight Sparkle race her token from 0 to n according to die rolls. The game end once she move to n or over it. Help Twilight Sparkle calculated the probability she end the game exactly at n.
输入解释
Input contains multiple test cases (less than 200).
For each test case, only one line contains two integers m and n (1<=m, n<=10^9).
输出解释
For each case, output the corresponding result, rounded to 5 digits after the decimal point.
输入样例
3 5
6 10
输出样例
0.49794
0.28929
来自杭电HDUOJ的附加信息
Recommend heyang

该题目是Virtual Judge题目,来自 杭电HDUOJ

题目来源 BestCoder Round #7

源链接: HDU-4987

最后修改于 2020-10-25T23:18:43+00:00 由爬虫自动更新

共提交 0

通过率 --%
时间上限 内存上限
2000/1000MS(Java/Others) 32768/32768K(Java/Others)