随笔分类 - Codeforces
摘要：题目链接：传送门 题解： 设定dp[i][j]在深度为i下，使用j个节点的方案数 显然的转移方程组就是 dp[h][n] = dp[h-1][i] * dp[h-1][n-i-1] + 2*dp[h-1][i]*dp[h-2][n-i-1]; 卷积形式 利用FFT加速求解dp[h] 下面是AC代码
阅读全文
摘要：D. The Bakery Some time ago Slastyona the Sweetmaid decided to open her own bakery! She bought required ingredients and a wonder-oven which can bake s
阅读全文
摘要：E. Liar The first semester ended. You know, after the end of the first semester the holidays begin. On holidays Noora decided to return to Vičkopolis.
阅读全文
摘要：D. My pretty girl Noora In Pavlopolis University where Noora studies it was decided to hold beauty contest "Miss Pavlopolis University". Let's describ
阅读全文
摘要：C. Hacker, pack your bags! It's well known that the best way to distract from something is to do one's favourite thing. Job is such a thing for Leha.
阅读全文
摘要：B. Crossword solving Erelong Leha was bored by calculating of the greatest common divisor of two factorials. Therefore he decided to solve some crossw
阅读全文
摘要：A. I'm bored with life Holidays have finished. Thanks to the help of the hacker Leha, Noora managed to enter the university of her dreams which is loc
阅读全文
摘要：E. Thief in a Shop A thief made his way to a shop. As usual he has his lucky knapsack with him. The knapsack can contain k objects. There are n kinds
阅读全文
摘要：E. Okabe and El Psy Kongroo Okabe likes to take walks but knows that spies from the Organization could be anywhere; that's why he wants to know how ma
阅读全文
摘要：F. Group Projects F. Group Projects There are n students in a class working on group projects. The students will divide into groups (some students may
阅读全文
摘要：C. Karen and Supermarket On the way home, Karen decided to stop by the supermarket to buy some groceries. She needs to buy a lot of goods, but since s
阅读全文
摘要：E. Army Creation As you might remember from our previous rounds, Vova really likes computer games. Now he is playing a strategy game known as Rage of
阅读全文
摘要：E. Scheme To learn as soon as possible the latest news about their favourite fundamentally new operating system, BolgenOS community from Nizhni Tagil
阅读全文
摘要：F. Leha and security system Bankopolis, the city you already know, finally got a new bank opened! Unfortunately, its security system is not yet workin
阅读全文
摘要：E. Prairie Partition It can be shown that any positive integer x can be uniquely represented as x = 1 + 2 + 4 + ... + 2k - 1 + r, where k and r are in
阅读全文
摘要：题目链接：点这里 题意： 1~N标号的球 现在A有C个，B有C个 每次可以随机得到D个不同的球(1~N);问你A或B中的C个球都出现一次的 期望次数 题解： dp[i][j][k]表示 随机出现了i个仅仅属于A的球的个数，仅仅属于B的球的个数，同时属于A,B的球的个数
阅读全文
摘要：题目链接：点这里 题意： 让你构造一个长度范围在[A,B]之间 字符串(大小写字母，数字)，问你有多少种方案 需要满足条件一下： 1:构成串中至少包含一个数字，一个大写字母，一个小写字母； 2:不能包含给定的N个病毒串 3:遵循一堆映射规则 题解： 将病毒串建立AC自动机 设定dp[i][j] [0
阅读全文
摘要：C. Divide by Three A positive integer number n is written on a blackboard. It consists of not more than 105 digits. You have to transform it into a be
阅读全文
摘要：D. Felicity's Big Secret Revealed The gym leaders were fascinated by the evolutions which took place at Felicity camp. So, they were curious to know a
阅读全文
摘要：F. PolandBall and Gifts It's Christmas time! PolandBall and his friends will be giving themselves gifts. There are n Balls overall. Each Ball has some
阅读全文
浙公网安备 33010602011771号