delete pics to save space

1.1122.cpp

@@ -0,0 +1,38 @@
+#include<cstdio>
+#include<cstring>
+#include<algorithm>
+#include<vector>
+using namespace std;
+const int maxn=16005;
+int n,a[maxn],f[maxn];
+vector<int> G[maxn];
+void dfs(int u,int fa)
+{
+	f[u]=a[u];
+	for(int i=0;i<G[u].size();i++)
+	{
+		int v=G[u][i];
+		if(v==fa) continue;
+		dfs(v,u);
+		if(f[v]>0) f[u]+=f[v];
+	}
+}
+int main()
+{
+	#ifdef local
+	freopen("pro.in","r",stdin);
+	#endif
+	scanf("%d",&n);
+	for(int i=1;i<=n;i++) scanf("%d",&a[i]);
+	for(int i=1;i<=n-1;i++)
+	{
+		int u,v; scanf("%d%d",&u,&v);
+		G[v].push_back(u);
+		G[u].push_back(v);
+	}
+	dfs(1,-1);
+	int res=f[1];
+	for(int i=2;i<=n;i++) res=max(res,f[i]);
+	printf("%d\n",res);
+	return 0;
+}