摘要： DescriptionThere is a hill with n holes around. The holes are signed from 0 to n-1.A rabbit must hide in one of the holes. A wolf searches the rabbit ... 阅读全文

摘要： SubmitStatusDescriptionSometimes some mathematical results are hard to believe. One of the common problems is the birthday paradox. Suppose you are in... 阅读全文

摘要： E -期望（经典问题）Time Limit:1000MSMemory Limit:32768KB64bit IO Format:%lld & %lluSubmitStatusDescriptionGiven a dice withnsides, you have to find the expect... 阅读全文

摘要： DescriptionYou are in a cave, a long cave! The cave can be represented by a1 x Ngrid. Each cell of the cave can contain any amount of gold.Initially y... 阅读全文

摘要： http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=30728一个立体方块，每个单位方块都是关闭状态，每次任两个点，以这两点为对角线的一个立方体状态都会进行一次转变，（开变成关，关变成开）如此进行k次后，问开着的灯的期望值思路：枚举... 阅读全文

摘要： http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=18546题意：有n个人会去超市，其中只有r个人会买东西，每个人独自买东西的概率会给出，问这一群人去买东西，第i个人属于r之中的概率是多少思路：首先得了解什么是条件概率.条件概率：... 阅读全文

摘要： ---恢复内容开始---http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=31471题意，两辆火车，分别会在[t1,t2],[s1,s2]的时间段停留在同一个站点w分钟，问两辆火车能够在这个站点相遇的概率。思路，枚举每一种情况，把... 阅读全文

摘要： 推荐在线例题：http://acm.nyist.net/JudgeOnline/problem.php?pid=16题摘：矩形嵌套时间限制：3000ms | 内存限制：65535KB难度：4描述有n个矩形，每个矩形可以用a,b来描述，表示长和宽。矩形X(a,b)可以嵌套在矩形Y(c,d)中当且仅当a... 阅读全文

摘要： K -背包Time Limit:1000MSMemory Limit:32768KB64bit IO Format:%I64d & %I64uSubmitStatusDescriptionNow you are asked to measure a dose of medicine with a b... 阅读全文

摘要： DescriptionWe give the following inductive definition of a “regular brackets” sequence:the empty sequence is a regular brackets sequence,ifsis a regul... 阅读全文