这题主要是推公式…… ;}…

思路:五边形数定理!!! 五边形数定理是一个由欧拉发现的数学定理,描述欧拉函数展开式的特性.欧拉函数的展开式如下: 亦即 欧拉函数展开后,有些次方项被消去,只留下次方项为1, 2, 5, 7, 12, ...的项次,留下来的次方恰为广义五边形数. 若将上式视为幂级数,其收敛半径为1,不过若只是当作形式幂级数(formal power series)来考虑,就不会考虑其收敛半径. 欧拉函数的倒数是分割函数的母函数,亦即: 其中为k的分割函数. 上式配合五边形数定理,可以得到 考虑项的系数,在 n>…

Integer Partition Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 524 Accepted Submission(s): 238 Problem Description Given n, k, calculate the number of different (unordered) partitions of n such…

Partition Time Limit: 6000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 954 Accepted Submission(s): 545 Problem Description How many ways can the numbers 1 to 15 be added together to make 15? The technical term…

Partition Time Limit: 6000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 954 Accepted Submission(s): 545 Problem Description How many ways can the numbers 1 to 15 be added together to make 15? The technical term…

ACM ICPC Central Europe Regional Contest 2013 Jagiellonian University Kraków Problem A: Rubik’s RectangleProblem B: What does the fox say?Problem C: Magical GCDProblem D: SubwayProblem E: EscapeProblem F: DraughtsProblem G: History courseProblem H: C…

传送门:http://acm.hdu.edu.cn/showproblem.php?pid=6300 Triangle Partition Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 132768/132768 K (Java/Others)Total Submission(s): 2964    Accepted Submission(s): 1474Special Judge Problem Description Chia…

JSU 2013 Summer Individual Ranking Contest - 5 密码:本套题选题权归JSU所有,需要密码请联系(http://blog.csdn.net/yew1eb). 一.套题分析:该套题难度不大,适合入门有一定基础的ACMer用于练习. 二.考点:逻辑思维.基础数论.数位运算基础.深度优先搜索.动态规划. 三.竞赛形式:个人赛 四.解题时间:3小时 五.题目情况: A. BNU ACM校队时间安排表        B. 硬币水题II        C. 沙漠之…

Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description Alice and Bob are playing together. Alice is crazy about art and she has visited many museums around the world. She has…

任意门:http://acm.hdu.edu.cn/showproblem.php?pid=6319 Problem A. Ascending Rating Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 5943    Accepted Submission(s): 2004 Problem Description Before…

POJ 上的一套水题,哈哈~~~,最后一题很恶心,不想写了~~~ Rope Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7410   Accepted: 2603 Description Plotters have barberically hammered N nails into an innocent plane shape, so that one can see now only heads. Moreove…

tree Time Limit: 8000ms Memory Limit: 262144KB This problem will be judged on HDU. Original ID: 539064-bit integer IO format: %I64d      Java class name: Main   Given a rooted tree(node 1 is the root) with n nodes. The ithnode has a positive value vi…

Area of Mushroom Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 2390    Accepted Submission(s): 578 Problem Description Teacher Mai has a kingdom with the infinite area. He has n students guard…

Differencia Time Limit: 10000/10000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 601    Accepted Submission(s): 173 Problem Description Professor Zhang has two sequences a1,a2,...,an and b1,b2,...,bn. He wants to…

Rigid Frameworks Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 337    Accepted Submission(s): 273 Problem Description Erik Demaine is a Professor in Computer Science at the Massachusetts Insti…

2012 Multi-University Training Contest 9 / hdu4389 打巨表,实为数位dp 还不太懂 先这样放着.. 对于打表,当然我们不能直接打,这里有技巧.我们可以这样:每隔100000我们统计一次,这样在10^9范围内,我们得到10000个数. 然后就很好解决了... 数位dp:http://blog.csdn.net/acdreamers/article/details/9318727 #include<iostream> #include<cst…

2014 Multi-University Training Contest 9#11 Killing MonstersTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 562    Accepted Submission(s): 308 Problem Description Kingdom Rush is a popular TD…

2014 Multi-University Training Contest 9#6 Fast Matrix CalculationTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 424    Accepted Submission(s): 219 Problem Description One day, Alice and Bob…

8/11 2016 Multi-University Training Contest 1 官方题解 老年选手历险记 最小生成树+线性期望 A Abandoned country(BH) 题意: 1. 求最小生成树 2. 求在某一棵最小生成树任意两点的最小距离的期望值. 思路: 首先题目说了边权值都是不同的,所以最小生成树唯一.那么只要统计出最小生成树的每一条边在“任意两点走经过它“的情况下所贡献的值,发现在一棵树里,一条边所贡献的次数为,sz[v]表示v子树包括节点v的个数.如下图所示,红边所…

8/13 2016 Multi-University Training Contest 2官方题解 数学 A Acperience(CYD)题意: 给定一个向量,求他减去一个  α(>=0)乘以一个值为任意+1或-1的B向量后得到向量,求这个向量膜的最小值思路: 展开式子,当时最小,结果为. 代码: #include <bits/stdc++.h> using namespace std; long long w,a,b,c,a2; long long gcd(long long x,l…

5/11 2016 Multi-University Training Contest 3官方题解 2016年多校训练第三场 老年选手历险记 暴力 A Sqrt Bo(CYD) 题意:问进行多少次开根号向下取整能使给定的值为1,若为5次以上,则输出TAT: 思路: 有5次这个限制,得知值最大为10的11次方左右,存下后运算即可,注意初始值为0时运算的次数是大于5次的,输出TAT: 代码: #include <bits/stdc++.h> using namespace std; char st…

6/12 2016 Multi-University Training Contest 4官方题解 KMP+DP A Another Meaning(CYD) 题意: 给一段字符,同时给定你一个单词,这个单词有双重意思,字符串中可能会有很多这种单词,求这句话的意思总数:hehe. 思路: 可以用kmp算法快速求出串中的单词数量,若单词是分开的,每个单词有两种意思,可以直接相乘,若两个及以上单词在原串中是有交集的,那么数量不是直接相乘,发现这片连在一起的单词数量dp[i]=dp[i-1]+dp[j…

6/12 2016 Multi-University Training Contest 5 期望+记忆化DP A ATM Mechine(BH) 题意: 去ATM取钱,已知存款在[0,K]范围内,每一次输入取出钱的金额,如果大于存款,ATM会发出警报,最多W次,问能在W次内取出所有存款的取款次数的期望值. 思路: 设dp[k][w]表示范围存款在[0,k]内,还有w次报警机会的期望值.状态转移方程: 代码: #include <bits/stdc++.h> const int N = 2e3…

5/12 2016 Multi-University Training Contest 6 官方题解 打表找规律/推公式 A A Boring Question(BH) 题意: ,意思就是在[0,n]里选择m个数字的相邻数字二项式组合的积的总和. 思路: 想了好久,不会,但是这题有300多人过,怀疑人生... 打了个表: n=0, m=2, ans=1n=1, m=2, ans=3n=2, m=2, ans=7n=3, m=2, ans=15n=4, m=2, ans=31n=5, m=2, a…

PowMod Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 1008    Accepted Submission(s): 341 Problem Description Declare:k=∑mi=1φ(i∗n) mod 1000000007 n is a square-free number. φ is the Euler's…

Subway Time Limit: 7000/3500 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 860    Accepted Submission(s): 126Special Judge Problem Description jiefangxuanyan and yiyi cat are universally acknowledged model couple…

Game Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 588    Accepted Submission(s): 146 Problem Description   Sea5 and wzh are playing games. There are some guards on an n × m chessboard. Every…

solved 7/11 2016 Multi-University Training Contest 10 题解链接 分类讨论 1001 Median(BH) 题意: 有长度为n排好序的序列,给两段子序列[l1,r1],[l2,r2]构成新的序列,问中间的数字. 思路: 根据不同情况分类讨论即可.时间复杂度O(1). 代码: #include <bits/stdc++.h> const int N = 1e5 + 5; int a[N]; int n, m; int l1, r1, l2, r…

solved 1/13 2016 Multi-University Training Contest 9 二分+最大权闭合图 Less Time, More profit(BH) 题意就是有n个工厂,m个商店 每个工厂有建造时间ti,花费payi 每个商店和k个工厂有关,如果这k个工厂都建造了,那么能获利proi 问你求收益(∑pro−∑pay)≥L时,首先满足时间t最小,其次是收益p最大 首先二分时间的答案,然后看那些工厂能建造,然后工厂是花费,商店是收益,并且要与商店有关的工厂都建造了,才能…

solved 4/11 2016 Multi-University Training Contest 8 贪心 1001 Ball(BH) 代码: #include <bits/stdc++.h> const int N = 1000 + 5; std::pair<int, int> a[N]; int n, m; int main() { int T; scanf ("%d", &T); while (T--) { scanf ("%d%d&…