delete pics to save space

1.3806.cpp

@@ -0,0 +1,83 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+using namespace std;
+const int maxn=10005;
+struct Edge { int v,w; Edge *next; };
+Edge mem[maxn*2],*G[maxn],*ecnt=mem;
+inline void AddEdge(int u,int v,int w) { ecnt->v=v; ecnt->w=w; ecnt->next=G[u]; G[u]=ecnt++; }
+int n,m,k,res,Siz,rt,cnt;
+bool vis[maxn];
+int f[maxn],sz[maxn],dis[maxn];
+void GetRoot(int u,int fa)
+{
+	f[u]=0; sz[u]=1;
+	for(Edge *it=G[u];it;it=it->next)
+	{
+		int v=it->v;
+		if(vis[v]||v==fa) continue;
+		GetRoot(v,u);
+		f[u]=max(f[u],sz[v]); sz[u]+=sz[v];
+	}
+	f[u]=max(f[u],Siz-f[u]);
+	if(f[u]<f[rt]) rt=u;
+}
+void GetDis(int u,int fa,int d)
+{
+	for(Edge *it=G[u];it;it=it->next)
+	{
+		int v=it->v;
+		if(vis[v]||v==fa) continue;
+		dis[++cnt]=d+it->w;
+		GetDis(v,u,dis[cnt]);
+	}
+}
+int GetAns(int u,int d)
+{
+	dis[cnt=1]=d;
+	GetDis(u,0,d);
+	sort(dis+1,dis+1+cnt);
+	int l=1,res=0;
+	while(l<cnt&&dis[l]+dis[cnt]<k) ++l;
+	while(l<cnt&&k-dis[l]>=dis[l])
+	{
+		auto it=equal_range(dis+l+1,dis+cnt+1,k-dis[l]);
+		res+=it.second-it.first;
+		++l;
+	}
+	return res;
+}
+void dfs(int u)
+{
+	vis[u]=true; res+=GetAns(u,0);
+	for(Edge *it=G[u];it;it=it->next)
+	{
+		int v=it->v;
+		if(vis[v]) continue;
+		res-=GetAns(v,it->w);
+		Siz=sz[v]; rt=0;
+		GetRoot(v,u);
+		dfs(v);
+	}
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d%d",&n,&m);
+	int a,b,c;
+	for(int i=0;i<n-1;i++)
+	{
+		scanf("%d%d%d",&a,&b,&c);
+		AddEdge(a,b,c); AddEdge(b,a,c);
+	}
+	while(m-->0)
+	{
+		scanf("%d",&k);
+		res=0; memset(vis,0,sizeof(vis)); Siz=n; sz[0]=1e9+7;
+		dfs(1);
+		puts(res?"AYE":"NAY");
+	}
+	return 0;
+}