C. MUH and House of Cards   Polar bears Menshykov and Uslada from the zoo of St. Petersburg and elephant Horace from the zoo of Kiev decided to build a house of cards. For that they've already found a hefty deck of n playing cards. Let's describe the…

MUH and House of Cards Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u Submit Status Practice CodeForces 471C Description Polar bears Menshykov and Uslada from the zoo of St. Petersburg and elephant Horace from the zoo o…

题目链接:http://codeforces.com/problemset/problem/471/C 题目意思:有 n 张卡,问能做成多少种不同楼层(floor)的 house,注意这 n 张卡都要用光.每层 floor 都由一定的 room 构成,每两个相邻 room 规定要有一个公共的ceiling.规定从上到下看,每层 floor 的 room 的数量呈递增的形式排布. 好容易想到构成最高层时用的最少数量的card需要多少.可以发现,每层的需要用到的card 可以用这个表达式表示: 3n…

1. CF 438D The Child and Sequence 大意: n元素序列, m个操作: 1,询问区间和. 2,区间对m取模. 3,单点修改 维护最大值, 取模时暴力对所有>m的数取模. 因为取模后至少减半, 复杂度$O(nlognlogC)$ 2. CF 431E Chemistry Experiment 大意: n个试管, 第$i$个试管有$a_i$单位水银, m个操作: 1, 修改$a_x$改为$v$. 2, 将$v$单位水倒入试管, 求一种方案使得有水的试管水银与水总量的最大…

题目链接: 传送门 Little Elephant and Cards time limit per test:2 second     memory limit per test:256 megabytes Description The Little Elephant loves to play with color cards. He has n cards, each has exactly two colors (the color of the front side and the…

Soldier and Cards time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Two bored soldiers are playing card war. Their card deck consists of exactly n cards, numbered from 1 to n, all values are…

题目链接:C. Soldier and Cards Two bored soldiers are playing card war. Their card deck consists of exactly n cards, numbered from 1 to n, all values are different. They divide cards between them in some manner, it's possible that they have different numb…

题意:给你一个只有‘.’和'#'的n*n的格子,问所有的'#'是不是只属于一个十字叉,如果不是输出NO,否则输出YES. #include <cstdio> #include <cstring> #include <algorithm> using namespace std; int n; ][]; ][]; int main() { scanf("%d",&n); ; i<=n; i++) { scanf("%s"…

http://codeforces.com/contest/387/problem/E 题意:给你n个数,然后在输入k个数,这k个数都在n个数中出现,进行每一次操作就是在n个数中选择长度为w的连续序列,然后删除这w个数中的最小的一个,然后你就会的到w个奖励,如何获得最多奖励? 思路:set+数状数组,数状数组用来记录在每一个连续的区间内数的个数,用来记录删除和添加数的个数,先对a数组中的数记录每一个数在序列中的位置,再对b数组进行标记,然后遍历1-n,被标记数,把它的位置放在set里面,没有被标…

\(\mathcal{Description}\)   Link.   打乱的 \(n\) 张编号 \(1\sim n\) 的数字排和 \(m\) 张鬼牌.随机抽牌,若抽到数字,将数字加入集合 \(S\):否则,还原牌堆(但不清空 \(S\)).若 \(S=[1,n]\) 且抽到鬼牌时结束抽牌.求期望抽牌次数.   \(n,m\le2\times10^6\). \(\mathcal{Solution}\)   称从初始牌堆开始抽牌一直到抽到鬼牌为一轮操作,发现结束时必然抽了若干个完整的轮且不能中…