CF896D Nephren Runs a Cinema 题意 售票员最开始没有纸币,每次来一个顾客可以给她一张.拿走她一张或不操作.求出不出现中途没钱给的情况 \(n\) 名顾客后剩余钱数在 \(l\sim r\) 的方案数. 思路 这是我们一道模拟赛题. 解法 1:套路组合计数.先不考虑不操作的顾客,那么就相当于是求二维平面不过一条直线到达一点的方案数.直接枚举操作顾客数,用组合数减去另外一个组合数然后乘上所有顾客中选这些顾客的方案数即可. 解法 2:暴力动态规划.每次从至多三个方向转移.…

[CF896D]Nephren Runs a Cinema 题意:一个序列中有n格数,每个数可能是0,1,-1,如果一个序列的所有前缀和都>=0且总和$\in [L,R]$,那么我们称这个序列是合法的.求合法序列的个数%P. n,L,R<=100000,P<=2*10^9 题解:先不考虑0的数,那么总数显然就是卡特兰数的变形.我们将卡特兰数转换成在二维平面上,从(0,0)走到(a,b),且不越过直线x=y的方案数.因为每个越过x=y的方案都可以转化成从(-1,1)走到(a,b)的方案,所…

Lakhesh loves to make movies, so Nephren helps her run a cinema. We may call it No. 68 Cinema. However, one day, the No. 68 Cinema runs out of changes (they don't have 50-yuan notes currently), but Nephren still wants to start their business. (Assume…

容易发现这些 vip 用户并没什么用,所以考虑枚举手持50元与100元的人共有多少个.设手持50元的人 \(a\) 个,手持100元的人 \(a - k\) 个,那么一共是 \(2*a - k\) 个人,最后手上会剩余 \(k\) 张50元钞票.用卡特兰数计算得到在这种情况下的方案数就是: \((\binom{2 * a - k}{a} - \binom{2 * a - k}{a + 1}) * \binom{n}{2 * a - k}\) 其中 \(l <= k <= r, 1 <=…

http://codeforces.com/contest/738/problem/C Vasya is currently at a car rental service, and he wants to reach cinema. The film he has bought a ticket for starts in t minutes. There is a straight road of length s from the service to the cinema. Let's…

C. Road to Cinema time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Vasya is currently at a car rental service, and he wants to reach cinema. The film he has bought a ticket for starts in t m…

C. Road to Cinema time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Vasya is currently at a car rental service, and he wants to reach cinema. The film he has bought a ticket for starts in t m…

          time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The cinema theater hall in Sereja's city is n seats lined up in front of one large screen. There are slots for personal possessions…

CINEMA 4D_百度百科 http://baike.baidu.com/view/49453.htm?fr=aladdin 转自百度贴吧 [教程]Cinema 4D R16新功能介绍及安装教程_c4d吧_百度贴吧 http://tieba.baidu.com/p/3339127719 安装过程没有出现太大的问题,一步一步来的. 就是注册机会算出以下几行序列号 Cinema4D Prime : 10600030531-HSWF-WFLD-FVGN-XCWP Cinema4D Broadcast…

Cinema in Akiba (CIA) is a small but very popular cinema in Akihabara. Every night the cinema is full of people. The layout of CIA is very interesting, as there is only one row so that every audience can enjoy the wonderful movies without any annoyan…