题意: 给你边权,起点和终点,有k次机会把某条路变为0,问你最短路是多长. 思路: 分层最短路模板题.题目有点坑(卡掉了SPFA,只能用dijkstra跑的算法). #include<iostream> #include<cstdio> #include<cstring> #include<queue> using namespace std; ,INF=~; int N,M,K; int S,T; *MAXM*(MAXK+)+MAXK+];)+]; voi…

题意: 给你一串数,问你如题. 思路: 我不是这样的作法,从后往前,先取00,再算%3==0的个数,往前推的时候有递推关系: #define IOS ios_base::sync_with_stdio(0); cin.tie(0); #include <cstdio>//sprintf islower isupper #include <cstdlib>//malloc exit strcat itoa system("cls") #include <io…

题意: 给你一个数,希望你能用最少的3的倍数或运算成它,让你输出答案. 思路: 进制%3有规律,1.2.4.8.16%3是1.2.1.2.1 ... 利用这一点分情况取一些位合成一些数就是答案了. #define IOS ios_base::sync_with_stdio(0); cin.tie(0); #include <cstdio>//sprintf islower isupper #include <cstdlib>//malloc exit strcat itoa sys…

思路: O(n)建一颗笛卡尔树,再O(n)dfs向上合并答案就行了. #define IOS ios_base::sync_with_stdio(0); cin.tie(0); #include <cstdio>//sprintf islower isupper #include <cstdlib>//malloc exit strcat itoa system("cls") #include <iostream>//pair #include &l…

题意: 给你n个基,q个询问,每个询问问你能不能 l~r 的所有基都能表示 x . 思路: 建一颗线性基的线段树,up就是求交的过程,按照线段树区间查询的方法进行check就可以了. #define IOS ios_base::sync_with_stdio(0); cin.tie(0); #include <cstdio>//sprintf islower isupper #include <cstdlib>//malloc exit strcat itoa system(&qu…

题意: 给你一棵树,树上有些点是有人的,问你选一个点,最短的(最远的那个人的距离)是多少. 思路: 其实就是树的直径,两遍dfs,dfs第二遍的时候遇到人就更新直径就行了,ans是/2,奇数的话+1. #define IOS ios_base::sync_with_stdio(0); cin.tie(0); #include <cstdio>//sprintf islower isupper #include <cstdlib>//malloc exit strcat itoa s…

链接:https://www.nowcoder.com/acm/contest/141/H来源:牛客网 Eddy has solved lots of problem involving calculating the number of coprime pairs within some range. This problem can be solved with inclusion-exclusion method. Eddy has implemented it lots of times…

链接:https://www.nowcoder.com/acm/contest/143/J来源:牛客网 There are n students going to travel. And hotel has two types room:double room and triple room. The price of a double room is p2 and the price of a triple room is p3 Now you need to calulate the min…

目录 题意: 分析: @(2019牛客暑期多校训练营(第八场)E_Explorer) 题意: 链接 题目类似:CF366D,Gym101652T 本题给你\(n(100000)\)个点\(m(10000)\)条边,每无向边允许通过编号在\([Li,Ri](1\le Li\le Ri\le 1e9)\)内的人,问从\(1\)到\(n\)能通过多少个人. 分析: 赛中艹了30多发暴力无济于事... 因为以前做过一道数据范围1000的原题,当时做法好像是离散化后枚举区间暴力跑\(dfs\)查询或者带着…

链接:https://www.nowcoder.com/acm/contest/140/J 来源:牛客网 White Rabbit has a rectangular farmland of n*m. In each of the grid there is a kind of plant. The plant in the j-th column of the i-th row belongs the a[i][j]-th type. White Cloud wants to help Whi…