zoj3201 Tree of Tree

#include<iostream>#include<cstdio>#include<algorithm>#include<cstring>#include<string>#include<vector>#include<queue>#include<cmath>#include<memory.h>#include<time.h>using namespace std;#define inf 200000000long long dp[109][109],ans,w[109];int head[109],cnt,n,k;struct Node{long long from,to;}node[500];void clear(){memset(node,0,sizeof(node));memset(head,-1,sizeof(head));memset(dp,0,sizeof(dp));cnt=0;}void add(int a,int b){node[cnt].from=b;node[cnt].to=head[a];head[a]=cnt++;ans=-inf;}void dfs(int u,int fa){for(int i=0;i<=k;++i)dp[u][i]=-inf;dp[u][1]=w[u];for(int j=head[u];j!=-1;j=node[j].to){int v=node[j].from;if(v!=fa){dfs(v,u);for(int l=k;l>=1;--l){for(int i=k;i>=1;--i){if(dp[v][i]==-inf)continue;if(l+i>k || dp[u][l]==-inf)continue;dp[u][l+i]=max(dp[v][i]+dp[u][l],dp[u][l+i]);}}}}ans=max(ans,dp[u][k]);}int main(){while(scanf("%d %d",&n,&k)!=EOF){clear();for(int i=0;i<n;++i)scanf("%lld",&w[i]);for(int i=1;i<n;++i){int a,b;scanf("%d %d",&a,&b);add(a,b);add(b,a);}dfs(0,-1);cout<<ans<<endl;}return 0;}