100 lines
2.4 KiB
C++
100 lines
2.4 KiB
C++
#include <iostream>
|
|
#include <cstdio>
|
|
#include <cstring>
|
|
#include <queue>
|
|
using namespace std;
|
|
const int N=105;
|
|
int head[N],tot;
|
|
int dp[N][N*5];
|
|
struct Edge
|
|
{
|
|
int from,to,cost,pre;
|
|
Edge(){}
|
|
Edge(int a,int b,int c,int d){from=a;to=b;cost=c;pre=d;}
|
|
}edge[N*3];
|
|
void addEdge(int u,int v,int cost)
|
|
{
|
|
edge[tot]=Edge(u,v,cost,head[u]);
|
|
head[u]=tot++;
|
|
}
|
|
int spfa(int st,int ed)
|
|
{
|
|
queue<int> que;
|
|
int vis[N],dis[N],pre[N];
|
|
memset(vis,0,sizeof(vis));
|
|
memset(dis,0x7f,sizeof(dis));
|
|
memset(pre,-1,sizeof(pre));
|
|
que.push(st);
|
|
vis[st]=1; dis[st]=0;
|
|
while(!que.empty())
|
|
{
|
|
int u=que.front();
|
|
que.pop(); vis[u]=0;
|
|
for(int i=head[u];i!=-1;i=edge[i].pre)
|
|
{
|
|
int v=edge[i].to,cost=edge[i].cost;
|
|
if(dis[v]>dis[u]+cost)
|
|
{
|
|
dis[v]=dis[u]+cost;
|
|
pre[v]=i;
|
|
if(!vis[v])
|
|
{
|
|
vis[v]=1;
|
|
que.push(v);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
for(int i=ed;i!=st;i=edge[pre[i]].from)
|
|
{
|
|
edge[pre[i]].cost=0;
|
|
edge[pre[i]^1].cost=0;
|
|
}
|
|
return dis[ed];
|
|
}
|
|
void dfs(int u,int fa,int coin)
|
|
{
|
|
for(int e=head[u];e!=-1;e=edge[e].pre)
|
|
{
|
|
int v=edge[e].to,cost=edge[e].cost*2;
|
|
if(v==fa||coin<cost) continue;
|
|
dfs(v,u,coin-cost);
|
|
for(int i=coin;i>=cost;i--)
|
|
{
|
|
for(int j=0;j+cost<=i;j++)
|
|
{
|
|
if(dp[u][i-j-cost]!=-1&&dp[v][j]!=-1)
|
|
dp[u][i]=max(dp[u][i],dp[u][i-j-cost]+dp[v][j]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
int main()
|
|
{
|
|
int n,t;
|
|
while(scanf("%d%d",&n,&t)!=EOF)
|
|
{
|
|
tot=0;
|
|
memset(dp,-1,sizeof(dp));
|
|
memset(head,-1,sizeof(head));
|
|
for(int i=0;i<n-1;i++)
|
|
{
|
|
int a,b,c;
|
|
scanf("%d%d%d",&a,&b,&c);
|
|
addEdge(a,b,c);
|
|
addEdge(b,a,c);
|
|
}
|
|
for(int i=1;i<=n;i++) scanf("%d",&dp[i][0]);
|
|
t-=spfa(1,n);
|
|
if(t<0) puts("Human beings die in pursuit of wealth, and birds die in pursuit of food!");
|
|
else
|
|
{
|
|
dfs(1,0,t);
|
|
int res=0;
|
|
for(int i=0;i<=t;i++) res=max(res,dp[1][i]);
|
|
printf("%d\n",res);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|