BaoBao has just found a rooted tree with n vertices and (n-1) weighted edges in his backyard. Among the vertices, of them are red, while the others are black. The root of the tree is vertex 1 and it's a red vertex.Let's define the cost of a red verte…

Press the Button Time Limit: 1 Second      Memory Limit: 131072 KB BaoBao and DreamGrid are playing a game using a strange button. This button is attached to an LED light (the light is initially off), a counter and a timer and functions as follows: W…

2018 ICPC 沈阳网络赛 Call of Accepted 题目描述:求一个算式的最大值与最小值. solution 按普通算式计算方法做,只不过要同时记住最大值和最小值而已. Convex Hull 题目描述:定义函数\(gay(x)\),若\(x\)是某个非\(1\)的数的平方的倍数,则\(gay(x)=0\),否则\(gay(x)=x^2\),求\(\sum_{num=1}^{n} ( \sum_{i=1}^{num} gay(x) ) mod p\) solution \[\sum…

2018 ICPC 徐州网络赛 A. Hard to prepare 题目描述:\(n\)个数围成一个环,每个数是\(0\)~\(2^k-1\),相邻两个数的同或值不为零,问方案数. solution 将环变成链,设\(f[i][0\)~\(2]\),分别表示与第一个数相同,与第一个数不同,与第一个数相同,与第一个数的反相同.然后\(dp\)即可. 时间复杂度:\(O(n)\) B. BE, GE or NE solution 根据题目描述\(dp\)即可. 时间复杂度:\(O(nm)\) C.…

题意:四个操作,区间加,区间每个数乘,区间的数变成 2^64-1-x,求区间和. 题解:2^64-1-x=(2^64-1)-x 因为模数为2^64,-x%2^64=-1*x%2^64 由负数取模的性质可知 也就 =(2^64-1)*x%2^64 所以 2^64-1-x=2^64-1+(2^64-1)*x 所以第三个操作也就变成了区间乘 和区间加.  然后就是树剖加线段树多重标记.表示这是第一次写多重标记,整体凭感觉,细节看题解,树剖有点点遗忘,不过还好.今天看群里说邀请赛没什么价值,,细想一下那…

大致题意: 给定一个n个点m条边的图,在可以把路径上至多k条边的权值变为0的情况下,求S到T的最短路. 数据规模: N≤100000,M≤200000,K≤10 建一个立体的图,有k层,每一层是一份原图,消耗一次把一条边权值变为0的机会 = 在立体图中升一层 然后跑堆优化dij就好了,会卡spfa. AC代码: #include<cstdio> #include<queue> #include<cstring> #define rep(i,a,b) for(int i=…

这个题,我也没想过我这样直接就过了 #include<bits/stdc++.h> using namespace std; ; typedef pair<int,int> pii; set<pii> G[maxn]; int main(){ int t,n,m,a,b,maxl; scanf("%d",&t); ;e<t;e++){ maxl=; ;i<maxn;i++)G[i].clear(); scanf("%d&…

最近打比赛不知道为什么总是怀疑自己 写完之后不敢交,一定跟学长说一遍自己的思路 然后发现"哦原来我是对的" 然后就A掉了…… 所以还是要有自信 Problem A 最大值直接输出m,最小值二分答案就可以了 . Problem B 现场没过这个题…… 原因是……ZJH的代码写错了一个细节(看起来很对) 所以有的时候并不能想当然. 我们的思路是这样的,首先把原来的树分成若干子树. 记录每个点管辖它的最近的红祖先.然后分离出来. 对于每个询问得到若干个子树,每个子树若干个被询问的点. 我们发…

There are N different kinds of transport ships on the port. The ith kind of ship can carry the weight of V[i]V[i] and the number of the ith kind of ship is 2c[i]-12^{C[i]} - 12. How many different schemes there are if you want to use these ships to t…

There are N children in kindergarten. Miss Li bought them N candies. To make the process more interesting, Miss Li comes up with the rule: All the children line up according to their student number (1...N), and each time a child is invited, Miss Li r…