Atcoder 全是神仙题-- 先变成能不能从 \(b\) 到 \(a\).操作变成一个数减掉旁边两个数. 考虑里面最大的且不和 \(a\) 中相等的那个数.它两边的数此时都不能操作,否则就减到非正数了. 而且应该要一直对这一位进行操作,直到等于 \(a_i\) 或者不是最大值为止.这样两边的数才能操作,或者真正确定无解. 用个堆模拟即可. 我的代码中复杂度--大概是两个 \(\log\) 吧.(辗转相除算一个) #include<bits/stdc++.h> using namespace…

从后往前做,每次将\(B_i\)减去相邻两个数,注意如果最大的数没有变成初始状态,那么肯定要减,否则相邻两边的就减不了,所以用堆维护.根据辗转相除的复杂度,\(O(n\log^2 n)\). #include<bits/stdc++.h> #define Rint register int #define MP make_pair #define fi first #define se second using namespace std; typedef long long LL; type…

题目大意 给你一个序列a和序列b 每次操作是a[i]+=a[i-1]+a[i+1] 问a经过最少几次操作可以得到b 分析 用堆维护a 每次取出最大的 撤销操作直到不能撤销 将新数放入堆 不断维护即可 代码 #include<iostream> #include<cstdio> #include<cstring> #include<string> #include<algorithm> #include<cctype> #include…

题目传送门 题意 这道题被某大佬改编拿来出成考试题,是长这个样子的: 好的,其实这才是真正的题意: 给定初始序列和最终序列,每次选择一个数变成自己和相邻2个数的和.问初始序列是否可以变为最终序列,若可以,问最少需要多少次. 分析 发现这道题有很多种操作方式,就算是写搜索暴力都不是很好写. 正难则反,考虑从末状态到初状态,就是一直减去左右两边的数. 如果中间的数大于两边的数之和,那么中间那个数一定要被操作(设$a,b,c$分别为$i-1,i,i+1$上的$B$值) 而且在$b>a+c$条件不被破坏…

D. Numbers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day Anna got the following task at school: to arrange several numbers in a circle so that any two neighboring numbers differs…

D. Numbers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day Anna got the following task at school: to arrange several numbers in a circle so that any two neighboring numbers differs…

Node.js is a platform for building fast and scalable server applications using JavaScript. Node.js is the runtime and NPM is the Package Manager for Node.js modules. VS Code has support for the JavaScript and TypeScript languages out-of-the-box as we…

  Prime Ring Problem  A ring is composed of n (even number) circles as shown in diagram. Put natural numbers into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle should always…

Meeting Minutes Merge Wordlist & Word Recite entry. (P0) – Done. Remove "Word Challenge" Button on user's wordlist expansion. (P0) – Done. Move "1453, 0" numbers inside the circle.(P2) – Done. Add "我认识" or "我不认识"…

Jump Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu Submit Status Practice UVA 1452 Integers 1, 2, 3,..., n are placed on a circle in the increasing order as in the following figure. We want to construct a sequence from these…