记录每一次操作的玩家为操作序列(去掉第一次),需要满足:$a$的个数为$n$且以$a$为结尾,$b$和$c$的个数分别不超过$m$和$k$ 其所对应的概率:每一个字符恰好确定一张卡牌,因此即$3^{n+m+k-|s|}$ 暴力枚举$b$和$c$的个数,即$\sum_{i=0}^{m}\sum_{j=0}^{k}{n+i+j-1\choose i}{n+j-1\choose j}3^{m+k-i-j}$ 将组合数用阶乘展开,即$\sum_{i=0}^{m}\sum_{j=0}^{k}\frac{(…

Text Postcards always spoil my holidays. Last summer, I went to Italy. I visited museums and sat in public gardens. A friendly waiter taught me a few words of Italian. Then he lent me a book. I read a few lines, but I did not understand a word. Every…

1.CardIO 识别 框架 GitHub 下载地址 配置 1.把框架整个拉进自己的工程,然后在 TARGETS => Build Phases => Link Binary With Libraries 里边分别加入下面这几个框架. Accelerate.framework MobileCoreServices.framework CoreMedia.framework AudioToolbox.framework AVFoundation.framework 2.在TARGETS =>…

容斥原理+状压 Card Collector Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1940    Accepted Submission(s): 907Special Judge Problem Description In your childhood, do you crazy for collecting the bea…

Install application pavucontrol Run pavucontrol You will see the configuration about sound card and mic card. If can not solve it, Kmix shoud be used and combine it with pavucontrol…

补充新闻:程序员黑餐馆系统 给自己饭卡里充钱 ,技术是双刃剑,小心,小心! 前言 从M1卡的验证漏洞被发现到现今,破解设备层出不穷,所以快速傻瓜式一键破解不是本文的重点,年轻司机将从本文中获得如下技能. 如果你想简单快速的上手,你可以选择ACR122-like,Proxmark3等容易购买到的操作简单的设备,或者有个带有NFC功能并安装有安卓Mifare Classic Tool (MCT)软件的手机也是个不错的选择. 本文基于树莓派加RC522,PN532模块试验,如果你是刚入门的Geek爱好…

Card Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 218    Accepted Submission(s): 86Special Judge Problem Description There are x cards on the desk, they are numbered from 1 to x. The score o…

[OpenJudge 3061]Flip The Card 试题描述 There are N× Ncards, which form an N× Nmatrix. The cards can be placed upwards or downwards. Now Acer is going to do some operations so that all the cards are placed upwards after the operations. In each operation,…

How and Where to Use the ORCA Card The Microsoft ORCA card provides unlimited rides on all buses, trains, and water taxis operated by participating transit agencies. The ORCA card uses contact-free technology similar to a building access card, so you…

Boot your Orange PI board from EMMC without SD Card inserted login insert your SD Card Run: sudo install_to_sdcard [btrfs] Copy the Code Your emmc Linux installation will be transfered to SD Card You can boot from that SD Card on another or the same…