Description 用$m$种颜色的彩球装点$n$层的圣诞树.圣诞树的第$i$层恰由$l[i]$个彩球串成一行,且同一层内的相邻彩球颜色不同,同时相邻两层所使用彩球的颜色集合不同. 求有多少种装点方案,答案对$p$取模. 只要任一位置上的彩球颜色不同,就算作不同的方案. Input 第一行三个整数$n,m,p$,表示圣诞树的层数.彩球的颜色数和取模的数. 接下来一行包含$n$个整数,表示$l[i]$. Output 一个整数表示答案. Sample Input 3 2 1000 3 1 2…

用$m$种颜色的彩球装点$n$层的圣诞树.圣诞树的第$i$层恰由$a_{i}$个彩球串成一行,且同一层内的相邻彩球颜色不同,同时相邻两层所使用彩球的颜色集合不 同.求有多少种装点方案,答案对$p$取模. 好神的计数问题,zwz Orz 题解思路来自黄学长hzwer的博客 先只考虑在一行内的彩球的方案数 定义$g[i][j]$表示一共有$i$个球串成一行,一共用了$j$种颜色的方案数 因为所有颜色都是等价的,我们可以利用最小表示法来简化计数,比如让颜色编号为$x+1$的球第一次出现的位置,在颜色编…

POJ 1759 Garland  这个题wa了27次,忘了用一个数来储存f[n-1],每次由于二分都会改变f[n-1]的值,得到的有的值不精确,直接输出f[n-1]肯定有问题. 这个题用c++交可以过,g++交过不了, f[i]=2+2*f[i-1]-f[i-2]; f[0]=A,f[1]=x; 二分枚举x的值,最终得到B的值(不是f[n-1]), 上述递推式是非齐次的二阶递推式,解其齐次特征方程,可以得到f[n-1]的齐次时的表达式,对于非齐次的,目前我还没法求出通式, B与f[n-1]的关…

Description The New Year garland consists of N lamps attached to a common wire that hangs down on the ends to which outermost lamps are affixed. The wire sags under the weight of lamp millimeter lower than the average height of the two adjacent lamps…

Garland Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 2365   Accepted: 1007 Description The New Year garland consists of N lamps attached to a common wire that hangs down on the ends to which outermost lamps are affixed. The wire sags…

C. Nice Garland time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('R',…

D. Diverse Garland time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('…

You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('R', 'G' and 'B' — colors of lamps in the garland). You have to recolor some lamps in this garland (recoloring a lamp means chang…

You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('R', 'G' and 'B' — colors of lamps in the garland). You have to recolor some lamps in this garland (recoloring a lamp means chang…

题目链接:http://codeforces.com/problemset/problem/1108/D time limit per test 1 secondmemory limit per test 256 megabytesinput standard inputoutput standard output You have a garland consisting of n lamps. Each lamp is colored red, green or blue. The colo…