倍增LCA板子,没有压行,可读性应该还可以.转载请随意. #include <cstdio> #include <cstring> #include <algorithm> #include <vector> using namespace std; const int maxn = 5e5; int n, m, rt; vector<int> G[maxn]; ; ]; int dep[maxn]; void dfs(int u, int fa…
题目描述 Farmer John has installed a new system of pipes to transport milk between the stalls in his barn (), conveniently numbered . Each pipe connects a pair of stalls, and all stalls are connected to each-other via paths of pipes. FJ is pumping milk…
裸的树上差分+倍增lca 每次从起点到终点左闭右开,这就有一个小技巧,要找到右端点向左端点走的第一步,然后差分就好了 #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #include<cmath> #define N 300005 using namespace std; int fa[N][20],dep[N],f[N],g[N],n,l[N];…
题意:一棵树,给两个点,求树上有多少点到他俩距离相等 倍增lca,分好多情况讨论.. #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #include<cmath> #define N 100500 using namespace std; int e=1,head[N]; struct edge{ int u,v,next; }ed[2*N];…
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…
描述 A 国有 n 座城市,编号从 1 到 n,城市之间有 m 条双向道路.每一条道路对车辆都有重量限制,简称限重.现在有 q 辆货车在运输货物,司机们想知道每辆车在不超过车辆限重的情况下,最多能运多重的货物. 输入 第一行有两个用一个空格隔开的整数 n,m,表示 A 国有 n 座城市和 m 条道路. 接下来 m 行每行 3 个整数 x.y.z,每两个整数之间用一个空格隔开,表示从 x 号城市到 y 号城市有一条限重为 z 的道路.注意:x 不等于 y,两座城市之间可能有多条道路. 接下来一行有…
