happybob @ 2022-07-14 12:07:02
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
using namespace std;
const int N = 1e5 + 5, M = 1e7 + 5;
struct Edge
{
int v, w;
Edge(int _v, int _w): v(_v), w(_w){}
};
vector<Edge> G[N];
int n, m;
int dis[N];
bool st[N], f[M];
int get_size(int u, int fa)
{
if (st[u]) return 0;
int res = 1;
for (int i = 0; i < G[u].size(); i++)
{
if (G[u][i].v != fa)
{
res += get_size(G[u][i].v, u);
}
}
return res;
}
int get_wc(int u, int fa, int& wc, int tot)
{
if (st[u]) return 0;
int sum = 1, maxn = 0;
for (int i = 0; i < G[u].size(); i++)
{
if (G[u][i].v != fa)
{
int v = get_wc(G[u][i].v, u, wc, tot);
maxn = max(maxn, v);
sum += v;
}
}
maxn = max(maxn, tot - sum);
if (maxn <= tot / 2) wc = u;
return sum;
}
void get_dist(int u, int fa, int& c, int w)
{
if (st[u]) return;
dis[++c] = w;
for (int i = 0; i < G[u].size(); i++)
{
int nx = G[u][i].v;
if (nx == fa) continue;
get_dist(fa, u, c, w + G[u][i].w);
}
}
void Init(int u)
{
if (st[u]) return;
get_wc(u, -1, u, get_size(u, -1));
st[u] = true;
int cur = 0;
for (int i = 0; i < G[u].size(); i++)
{
int nx = G[u][i].v;
get_dist(nx, u, cur, G[u][i].w);
}
for (int i = 1; i <= cur; i++)
{
if (dis[i] <= (int)1e7) f[dis[i]] = 1;
for (int j = i + 1; j <= cur; j++)
{
int w = dis[i] + dis[j];
if (w > (int)1e7) continue;
f[w] = 1;
//printf("%d\n", w);
}
}
for (int i = 0; i < G[u].size(); i++) Init(G[u][i].v);
}
int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i < n; i++)
{
int u, v, w;
scanf("%d%d%d", &u, &v, &w);
G[u].push_back(Edge(v, w));
G[v].push_back(Edge(u, w));
}
Init(1);
while (m--)
{
int k;
scanf("%d", &k);
if (f[k]) printf("AYE\n");
else printf("NAY\n");
}
return 0;
}
by happybob @ 2022-07-14 12:07:49
全都是read N,expected A
by happybob @ 2022-07-14 12:27:40
此贴终结