现场赛大佬打印的代码,观摩了一哈. 写了注释,贴一下,好好学习.%%%PKU 代码: //树上差分(LCA) #include<bits/stdc++.h> #define For(i,x,y) for (int i=x;i<y;i++) #define fi first #define se second #define pb push_back #define mp make_pair #define lf else if #define dprintf(...) fprintf(s…

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.…

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&…

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…

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…

A 矩阵树定理可以用于最小生成树计数,最直观的做法就是求个mst,再用矩阵树定理求最小生成树个数,但是n<=1e5,显然不是o(n^3)可以做出来的. 考虑随机数据生成器,固定1e5的边,但是边权在unsigned long long的范围内随机指定,由样例看出,即使是点数很少的情况下,最多也只有一个生成树 于是,我们猜测,只需要做一遍最小生成树,并假定不会有更多的生成树就可以了. #include<bits/stdc++.h> #define ull unsigned long lon…

Hello everyone! I am your old friend Rikka. Welcome to Xuzhou. This is the first problem, which is a problem about the minimum spanning tree (MST). I promise you all that this should be the easiest problemeasiest problem for most people. A minimum sp…

P2 : Heshen's Account Book Time Limit:1000ms Case Time Limit:1000ms Memory Limit:512MB Description Heshen was an official of the Qing dynasty. He made a fortune which could be comparable to a whole country's wealth by corruption. So he was known as t…

P1 : Jin Yong’s Wukong Ranking List Time Limit:1000ms Case Time Limit:1000ms Memory Limit:512MB Description Jin Yong was the most famous and popular Chinese wuxia (The one who fight bad people by his Wukong i.e. Wushu and Kongfu) novelist who lived i…

题目链接:http://codeforces.com/gym/102012/problem/A 题目给出的算法跑出的数据是真的水 #include<iostream> #include<algorithm> using namespace std; unsigned long long k1,k2; #define inf 0x3f3f3f3f #define mod 1000000007 int tot; unsigned long long xo() { unsigned lo…