嘟嘟嘟 题面:给一个序列中的,每一个数都减去一个实数x,使得到的新序列的max(最大连续和,|最小连续和|)最小.(|ai| <= 10000) 感性的想想,会发现最大连续和随x变大而变小,最小连续和随x变大而变大. 严格的证明:首先对于任意区间[L, R],|∑ai - x|一定是一个绝对值函数,则最大连续和就是把所有[L, R]的函数复合在一起,然后取max,画图可知,也是一个单峰函数.(似乎也不怎么严格) 那么max(最大连续和,|最小连续和|)就是一个单峰函数,于是用三分求解. 至于最大…

其实三分就是一个求单峰函数的最值的东西,用法比较统一.这个题就是观察发现不美好值是一个单峰函数,然后枚举t进行三分就行了. 题干: 给定一个长度为n的数组ai,求一个实数x,使得序列a1-x,a2-x,...,an-x的不美好程度最小. 不美好程度定义为,一个序列的所有连续子序列的糟糕程度的最大值. 糟糕程度定义为,一个序列的所有位置的和的绝对值. 输入 第一行n. 第二行n个数,表示ai. 输出 一个实数,精确到6位小数,表示最小不美好程度值. 代码: #include<iostream>…

C. Weakness and Poorness Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/578/problem/C Description You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the sequence a1 -…

E. Weakness and Poorness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the seq…

C. Weakness and Poorness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the seq…

[题目]C. Weakness and Poorness [题意]给定含n个整数的序列ai,定义新序列为ai-x,要使新序列的最大子段和绝对值最小,求实数x.n<=2*10^5. [算法]二分||三分||计算几何(凸包) [题解]Editorial 令正数最大子段和为A,负数最大子段和为B,绝对值是max(A,B).当x从小到大变化时,A由大变小,B由小变大. 容易发现这是一个下凸函数,可以用三分法求解. 但是,这道题卡精度(-11会WA,-12会T),解决方法是根据复杂度把循环次数卡到极限而不…

题目描述: E. Weakness and Poorness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a sequence of n integers a1, a2, ..., *a**n*. Determine a real number x such that the weakness…

https://vjudge.net/problem/CodeForces-578C —————————————————————————— 题目大意:序列的数-x,求最大连续子序列和的绝对值的最小值. ———————————————————————————— 没有绝对值的话,明显是单调增的. 将数全部翻转,明显是单调减的. 所以显然是单峰函数,可以三分x做. 要注意精度,循环200就差不多了,不要循环太多次不然会TLE. #include<cstdio> #include<cmath&g…

原题 题目定义了两个变量: poorness表示一个区间内和的绝对值. weakness表示一个所有区间最大的poornesss 题目要求你求一个x使得 a1 − x, a2 − x, ..., an − x这个序列的weakness最小 输出最小的weakness 显然,所求值是这样的一个函数 (因为是对abs取max,所以不可能出现有两个谷的不符合要求的函数) 所以我们可以三分,只有当x为ans时,我们才会得到最小值. 已知x时,如何求解最大子段和呢?,因为我们是取abs,所以在记录b[i]…

You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the sequence a1 - x, a2 - x, ..., an - x is as small as possible. The weakness of a sequence is defined as the maximum value of the poorness o…

time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the sequence a1 - x, a2 - x, ...…

题意:一个数组arr,一个数字x,要使arr-x的最大子段最小,问该最小值. 三分x,复杂度logn,内层是最大子段的模板,只能用n复杂度的.因为是绝对值最大,正负各求一次,取大的.精度卡得不得了,要1e-12左右才能过.看着数据才调出精度的. 乱码: //#pragma comment(linker,"/STACK:1024000000,1024000000") #include<iostream> #include<cstdio> #include<s…

显然f(x)是个凹函数,三分即可,计算方案的时候dp一下.eps取大了会挂精度,指定循环次数才是正解. #include<bits/stdc++.h> using namespace std; ; ; double a[maxn]; double d1[maxn],d2[maxn]; int n; inline double cal(double x) { ., a2 = .; ; i <= n; i++){ d1[i] = max(.,d1[i-])+a[i]-x; a1 = max(…

2017-08-27 17:24:07 writer:pprp 题意简述: • Codeforces 578C Weakness and poorness• 给定一个序列A• 一个区间的poorness定义为这个区间内和的绝对值• weakness等于所有区间最大的poorness• 求一个x使得,序列A全部减x后weakness最小• 1 ≤ n ≤ 2 * 1e5 这里用到了最大连续区间的和的知识点·,可以看上一篇博客 通过三分找最小值 AC代码如下: /* @theme:myprogram…

Raising Bacteria 题意:盒子里面的细菌每天会数量翻倍,你可以在任意一天放任意多的细菌,最后要使得某天盒子里面的细菌数量等于x,求至少要放多少个细菌 思路:显然,翻倍即为二进制左移一位,那么放入一个细菌,到第二天就变成2个二进制下即为1->10对于任意二进制数 如:1001110,只需要在第一天放1个,第4.5.6天各放一个,再等一天,就可以了.所以答案显然是x在二进制下1的个数. Finding Team Member 题意:2n个人,每两个人组合的队伍有aij的力量.每个人都希…

E. Weakness and Poorness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a sequence of n integers a1, a2, ..., an. Determine a real number x such that the weakness of the seq…

A. Raising Bacteria 计算一下x的bitcount就是答案. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; int bitcount(int x) { ; while(x) { ) ans++; x >>= ; } return ans; } int main() { int x…

Codeforces Round#320 Div2 先做个标题党,骗骗访问量,结束后再来写咯. codeforces 579A Raising Bacteria codeforces 579B Finding Team Member codeforces 579C A Problem about Polyline codeforces 579D "Or" Game codeforces 579E Weakness and Poorness codeforces 579F LCS Aga…

DimProduct DimSubcategory Dimcategory productpk subcategorypk categorypk sku subcategoryName categoryName productName categorypk subcategorypk Snow flake schema has one weakness, Take the product dimension sample, its has subcategory attribute. If we…

目录 概 主要内容 准则1 准则2 总策略 Hu S, Yu T, Guo C, et al. A New Defense Against Adversarial Images: Turning a Weakness into a Strength[C]. neural information processing systems, 2019: 1633-1644. @article{hu2019a, title={A New Defense Against Adversarial Images…

得益于Cydia Substrate框架,HOOK Native函数变得简单,也给脱壳带来方便. 像ijiami免费版,360,classes.dex被加密到so文件并运行时释放到内存,因此针对相关函数的HOOK脱壳就比较简单了. 但也有一些容易被针对的缺点: 1.代码可以在类加载时被修改.hook dexFileParse.__mmap2或memcmp 等可能dump出是修复前的dex 2.修改了odex的标志dey\n036,dumper在内存中搜索不到,将漏掉真正的odex 3.packe…

March 16, 2016 Problem statement:Given a 2D array (matrix) named M, print all items of M in a spiral order, clockwise.For example: M  =  1   2   3   4   5       6   7   8   9  10      11  12  13  14  15      16  17  18  19  20 The clockwise spiral pr…

Ionic Framework Ionic framework is the youngest in our top 5 stack, as the alpha was released in late November 2013. Built on top of the popular AngularJS framework from Google, Ionic utilizes AngularJS to provide the application structure, while Ion…

resource: On the Life-Long Learning Capabilities of a NELLI*: A Hyper-Heuristic Optimisation System Wikipedia Hyper-heuristic: https://en.wikipedia.org/wiki/Hyper-heuristic Wikipedia Heuristic: https://en.wikipedia.org/wiki/Heuristic_(computer_scienc…

原文转自:http://www.sellarafaeli.com/blog/native_javascript_data_binding Two-way data-binding is such an important feature - align your JS models with your HTML view at all times, to reduce boilerplate coding and enhance UX. We will observe two ways of d…

[原文链接:http://engineering.richrelevance.com/recommendations-thompson-sampling/.] [本文链接:http://www.cnblogs.com/breezedeus/p/3775339.html,转载请注明出处] Recommendations with Thompson Sampling 06/05/2014 • Topics: Bayesian, Big data, Data Science by Sergey Fel…

没了解过歌曲背景,总觉得像是一首女儿唱给母亲的歌= =也许是我的错觉 I will not make the same mistakes that you did 我不会重复你犯过的错误 I will not let myself Cause my heart so much misery 我不会让自己的心承受如此痛苦 I will not break the way you did 我不会破坏你选择的方式 You fell so hard 你吃尽苦头 I ve learned the hard…

Description After successive failures in the battles against the Union, the Empire retreated to its last stronghold. Depending on its powerful defense system, the Empire repelled the six waves of Union's attack. After several sleepless nights of thin…

Catalog . Linux attack vector . Grsecurity/PaX . Hardened toolchain . Default addition of the Stack Smashing Protector (SSP): Compiler Flag: GS . Automatic generation of Position Independent Executables (PIEs): System Characteristic + Compiler Flag:…

Tips for writing a paper 1. Tips for Paper Writing 2.• Before you write a paper • When you are writing a paper • The expression 3.Before you start writing a paper • State your Contribution • Organize your paper structure, See Everything as a Facet on…