[ACM][2018南京预赛]Sum】的更多相关文章

一.题面 样例输入: 2 5 8 样例输出: 8 14 二.思路 关键词:线性筛 在Zed的帮助下知道了这是一道线性筛的比较裸的题了.考试过程中肝这道题的时间最久,费了心思找到递推式后,发现根本不是在1s内能实现的东西.考试过程中大三学长选择了暴力打表打了几十KB...考后向Zed请教良久知道了线性筛.线性筛最基础的作用是筛出所有质数,时间复杂度仅为o(n).由于f(x)是“积性函数”(f(a * b) = f(a) * f(b)),所以也可以用线性筛处理. 三.代码 #include <cst…
一.题面 样例输入: 5 4 3 10 5 2 7 10 5 1 4 8 7 2 3 6 4 7 样例输出: 4 0 1 1 3 6 5 1 5 1 2 0 3 2 4 4 3 6 5 1 二.思路 关键词:线段树 这道题最难就难在看题吧...也许ACM的魅力之一便在于此——面对若干道题,你不知每一道题的难度是高是低,只能耐心地读清题面,审清题意,理清思路,方可知其是否在能力范围内以及预估耗时.考试过程中,我基本靠board来判断题目难度,清北大佬们先AC了哪些我就先做哪些...然而这道题似乎他…
一.题面 样例输入: 15 6 11 2 21 3 42 4 33 4 13 5 64 5 2 样例输出: 3 二.思路 关键词:分层BFS 考试时觉得题干意思很清晰——求可将k条边赋值为0的最短路.起初几个思路正确性均存疑,后来觉得应该要DP于是决定滞后了... 正解——分层BFS,个人认为思路与DP有些许相像,同时记录节点及当前已赋值为0的边数,则在跑最短路时(这里用的SPFA),可选择是否将该条边赋值为0,当且仅当已选边<k. 三.代码 #include <cstdio> #inc…
A square-free integer is an integer which is indivisible by any square number except 11. For example, 6 = 2 \cdot 36=2⋅3 is square-free, but 12 = 2^2 \cdot 312=22⋅3 is not, because 2^222 is a square number. Some integers could be decomposed into prod…
J. Sum 26.87% 1000ms 512000K   A square-free integer is an integer which is indivisible by any square number except 11. For example, 6 = 2 \cdot 36=2⋅3 is square-free, but 12 = 2^2 \cdot 312=22⋅3 is not, because 2^222 is a square number. Some integer…
G. Lpl and Energy-saving Lamps 42.07% 1000ms 65536K   During tea-drinking, princess, amongst other things, asked why has such a good-natured and cute Dragon imprisoned Lpl in the Castle? Dragon smiled enigmatically and answered that it is a big secre…
轻轻松松也能拿到区域赛名额,CCPC真的好难 An Olympian Math Problem 问答 只看题面 54.76% 1000ms 65536K   Alice, a student of grade 66, is thinking about an Olympian Math problem, but she feels so despair that she cries. And her classmate, Bob, has no idea about the problem. T…
ACM-ICPC 2018 南京赛区网络预赛 A. An Olympian Math Problem 计算\(\sum_{i=1}^{n-1}i\cdot i!(MOD\ n)\) \(\sum_{i=1}^{n-1}i\cdot i! = \sum_{i=1}^{n-1}[(i+1)!-i!](MOD\ n)=n!-1!(MOD\ n)=n-1\) #include<bits/stdc++.h> using namespace std; int T; long long n; int mai…
ACM-ICPC 2018 南京赛区网络预赛 E题 题目链接: https://nanti.jisuanke.com/t/30994 Dlsj is competing in a contest with n (0 < n \le 20)n(0<n≤20) problems. And he knows the answer of all of these problems. However, he can submit ii-th problem if and only if he has s…
题目链接:https://nanti.jisuanke.com/t/30991 Feeling hungry, a cute hamster decides to order some take-away food (like fried chicken for only 3030 Yuan). However, his owner CXY thinks that take-away food is unhealthy and expensive. So she demands her hams…