首页 > TAG信息列表 > Decorative
LED Decorative Light Supplier - LED Neon Application: 5 Advantages
In the past 100 years, lighting has gone a long way. LED decorative lighting is now designed to meet any visual need. Consumers find it difficult to choose between traditional and modern styles. These options are easily overwhelmed when choosing lights$Poj1037\ A\ Decorative\ Fence$ 计数类$DP$
Poj AcWing Description Sol 这题很数位$DP$啊, 预处理$+$试填法 $F[i][j][k]$表示用$i$块长度不同的木板,当前木板(第$i$块)在这$i$块木板中从小到大排在第$j$位,构成栅栏的方案数.$k=0$表示处于低位,$k=1$表示处于高位. $F[i][j][0]=\sum_{p=j}^{i-1}$ $F[i][j][1]=\suA decorative fence
A decorative fence 在\(1\sim n\)的全排列\(\{a_i\}\)中，只有大小交错的（即任意一个位置i满足\(a_{i-1}<a_i>a_{i+1}ora_{i-1}>a_i<a_{i+1}\)）排列方案才是合法的，询问合法的第c个方案的全排列，\(n\leq 20,c\leq 2^{63}\)。 解 首先是求第几个方案，自然要用试填法，而排列问题不同于普通递