2019 Multi-University Training Contest 2: 1010 Just Skip The Problem 自闭记 题意 多测.每次给你一个数\(n\),你可以同时问无数次,每次问的是一个数\(y_i\),你会得到的回答是\(x\&y_i\)是否为\(y_i\),问你问的最少的次数的种数\(\%1e6+3\),可以调换顺序 10min 得出数学方法 求\(n!\%1e6+3\). 50min 自闭 5min 写出裸暴力,优化10min,交一发TLE 30min 网上…

Hotaru's problem Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 907    Accepted Submission(s): 322 Problem Description Hotaru Ichijou recently is addicated to math problems. Now she is playing…

The shortest problem Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 346    Accepted Submission(s): 167 Problem Description In this problem, we should solve an interesting game. At first, we hav…

http://acm.hdu.edu.cn/showproblem.php?pid=6623 题意,给50000个1e18级别的数N,求它质因数分解里面的最小的指数(不算0) 比赛的时候给划了一个1e6以内的暴力判断,判断失效之后开平方根看看是不是质数平方,是则2不是则1.这个是题解的最后一步. 可惜没办法沿着这个思路走,就开始自闭了. 其实先暴力判断掉N的1/5次方内的质因数的指数,假如是1则直接退出了,否则要么不出现要么出现至少是2,记录剩余的数字为M.显然M是与N同级别的. 由于暴力掉了N…

链接:http://acm.hdu.edu.cn/showproblem.php?pid=6406 思路: 暴力,预处理三个前缀和:[1,n]桃子会被摘掉,1到当前点的最大值,1到当前点被摘掉的桃子的数量,然后我们枚举修改p点造成的所有影响,: 1,假如新输入的点比原先的点的值更大,那么我们对修改后p这个点的值和[1,p-1]的最大值关系进行分析,也就是分析前半段的影响:(1)如果p点大于1-p-1的最大值的时候我们直接利用前缀和O(1)得到[1,p-1]有多少个桃子被摘掉,然后加上当前这个.(…

6318.Swaps and Inversions 这个题就是找逆序对,然后逆序对数*min(x,y)就可以了. 官方题解:注意到逆序对=交换相邻需要交换的次数,那么输出 逆序对个数 即可. 求逆序对有4种操作,线段树 .BIT.归并排序.树状数组. 我敲了线段树.归并排序和树状数组版的. 关于这几种方法求逆序对,自行百度吧,懒了... 代码(线段树版-注意排序): //1010-找逆序对数-线段树求逆序对数 #include<iostream> #include<cstdio>…

这题的题意是给你一幅图,图里面有水滴.每一个水滴都有质量,然后再给你一个起点,他会在一開始的时候向四周发射4个小水滴,假设小水滴撞上水滴,那么他们会融合,假设质量大于4了,那么就会爆炸,向四周射出质量为一的水滴,问你在T时刻的时候,各个水滴的状态. #include <stdio.h> #include <string.h> #include <iostream> #include <algorithm> #include <math.h> #i…

线段树分治. 把size看成时间,相当于时间 $l$ 加入这条边,时间 $r+1$ 删除这条边. 注意把左右端点的关系. #include <bits/stdc++.h> ; int X[N], Y[N], top; struct DSU { int fa[N], sz[N]; int find(int x) { while (x != fa[x]) x = fa[x]; return x; } void merge(int x, int y) { x = find(x), y = find(…

由于每个元素贡献是线性的,那么等价于求每个元素出现在多少个异或和为$0$的子集内.因为是任意元素可以去异或,那么自然想到线性基.先对整个集合A求一遍线性基,设为$R$,假设$R$中元素个数为$r$,那么任取一个不在$R$内的元素,$R$中肯定存在一种取法能和这个元素异或和为$0$.同理,取定一个不在$R$内的元素,再随便取另外任意个不在$R$内的元素,$R$内仍然存在一种取法使得这个异或和为$0$.那么每个不在$R$内的元素包含在$2^{n - r - 1}$个集合内(其他不在$R$内的元素可以…

2019 Multi-University Training Contest 2 http://acm.hdu.edu.cn/contests/contest_show.php?cid=849 1005. Everything Is Generated In Equal Probability 考虑一个随机的排列的逆序对个数,显然对于两个数\(a,b\),他们位置是均匀排布的,也就是说有\(\frac{1}{2}\)的概率成为逆序对,并且是独立的. 所以一个长度为\(n\)的随机排列期望逆序对个…

Just A String Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 643    Accepted Submission(s): 182 Problem Descriptionsoda has a random string of length n which is generated by the following alg…

Leader in Tree Land Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 447    Accepted Submission(s): 185 Problem DescriptionTree land has n cities, connected by n−1 roads. You can go to any city f…

2019 Multi-University Training Contest 6 http://acm.hdu.edu.cn/contests/contest_show.php?cid=853 1002. Nonsense Time 这题比较神奇...有一个结论是:一个长度为\(n\)的随机排列的最长上升子序列期望长度为\(O(\sqrt n)\). 那么我们考虑倒着删数,每次暴力处理出当前任意一个最长上升子序列,然后删除\(x\)的时候判一下\(x\)在不在当前的序列中,在就重新求一遍,否则不…

2019 Multi-University Training Contest 4 http://acm.hdu.edu.cn/contests/contest_show.php?cid=851 1001. AND Minimum Spanning Tree 如果\(n\not =2^x-1\)那么答案为\(0\),可以这么构造: 对于\(i\ne 2^x-1\)把\(i\)连向第一个比\(i\)小的\(j\),并且\(i\&j=0\). 否则\(i\)连向\(i+1\),把这两个点绑在一起就好了…

2019 Multi-University Training Contest 8 C. Acesrc and Good Numbers 题意 \(f(d,n)\) 表示 1 到 n 中,d 出现的次数.求小于等于 x 的最大的 \(n\) 满足 \(f(d,n)=n\). 做法 令 \(g(d,n)=f(d,n)-f(n)\),我们要求小于等于 \(x\) 极大的零点. 注意到 \(n>10^{12}\) 一定不存在零点. [比赛时注意到了这点] Big-Small 战法. 取 B 等于 \(1…

2019 Multi-University Training Contest 7 A. A + B = C 题意 给出 \(a,b,c\) 解方程 \(a10^x+b10^y=c10^z\). trick hash! B.Bracket Sequences on Tree unsolved 做法 树hash,统计答案 然后疯狂wa,直到特判了最后两组数据... 假的AC F. Final Exam upsolved 题意 参加考试,确保通过 \(k\) 道题目. 复盘 先是认定了,所有题都复习相…

2019 Multi-University Training Contest 1 A. Blank upsolved by F0_0H 题意 给序列染色,使得 \([l_i,r_i]\) 区间内恰出现 k 种颜色. 做法 DP,\(dp[i][x][y][z]\) 表示考虑前 \(i\) 个位置,剩下 3 种颜色最后出现的位置为 \(x,y,z\) 的方案数 \((i\geq x \geq y \geq z)\) 复盘 比赛开始就提出了这个做法,但很遗憾,过题效率太低,再加上觉得 \(O(n^4…

2019 Multi-University Training Contest 2 A. Another Chess Problem B. Beauty Of Unimodal Sequence 题意 给一个序列,求下标字典序最小和字典序最大的,先增后减的序列. 解体过程 比赛时首先不知道字典序最小LIS怎么求. 试图枚举分界点.[解体的开始] 公无渡河,公竟渡河? 活鱼在摸鱼,rdc在划水,sdcgvhgj在水深火热. 做法 考虑字典序最小的LIS怎么求? 这是个经典问题,预处理前缀LIS后缀L…

2019 Multi-University Training Contest 5 A. fraction upsolved 题意 输入 \(x,p\),输出最小的 \(b\) 使得 \(bx\%p<b\) 做法 \(bx-py<b\),即 \(b(x-1)<py\),即 \(\frac{b}{y}<\frac{p}{x-1}\) 另一方面,\(bx>py\),即 \(\frac{p}{x}<\frac{b}{y}\) GCD 即可. B. three arrays un…

2019 Multi-University Training Contest 5 http://acm.hdu.edu.cn/contests/contest_show.php?cid=852 1004. Equation 把所有绝对值的零点排个序,然后解方程就好了. #include<bits/stdc++.h> using namespace std; // #define int long long void read(int &x) { x=0;int f=1;char ch=…

2019 Multi-University Training Contest 3 http://acm.hdu.edu.cn/contests/contest_show.php?cid=850 1004. Distribution of books 考虑二分答案,设当前二分出来的是\(x\). 设\(f_i\)表示前\(i\)个能分成最多的段数,使得每一段和都\(\leqslant x\). 转移显然,枚举一个\(j\),若\(s_i-s_j\leqslant x\)则转移,\(s_i\)表示前…

2019 Multi-University Training Contest 1 http://acm.hdu.edu.cn/contests/contest_show.php?cid=848 1001. Blank 这题我打比赛的时候想到正解了没敢写... 设\(f_{a,b,c,d}\)表示\(\{0,1,2,3\}​\)最后一次出现的位置排序之后的结果,那么每次枚举四种情况转移就好了. 复杂度\(O(Tn^4)\),由于转移的循环除了个\(4!\)的常数所以跑的很快. #include<b…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=6582 Path Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 3747    Accepted Submission(s): 1075 Problem Description Years later, Jerry fell in love…

Welcome Party Time Limit: 4000/4000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 875    Accepted Submission(s): 194 Problem Description The annual welcome party of the Department of Computer Science and Technolo…

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…

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…