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, ...…

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…

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…

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…

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…