2809: [Apio2012]dispatching 可并堆 左偏树

https://www.lydsy.com/JudgeOnline/problem.php?id=2809

板子题wa了一下因为输出ans没有lld

 #include<iostream>
 #include<cstdio>
 #include<algorithm>
 #include<cstring>
 #include<cmath>
 #include<queue>
 using namespace std;
 const int maxn=;
 int n,m;
 int ch[maxn][]={},siz[maxn]={},sum[maxn]={},cnt[maxn]={},rt[maxn]={};
 int fa[maxn]={},val[maxn]={},l[maxn]={};
 int y[maxn],nex[maxn]={},head[maxn]={},tot=;
 long long ans=;
 void init(int x,int yi){
     y[++tot]=yi;nex[tot]=head[x];head[x]=tot;
 }
 void updata(int x){
     siz[x]=siz[ch[x][]]+siz[ch[x][]]+;
     sum[x]=sum[ch[x][]]+sum[ch[x][]]+val[x];
 }
 int merge(int x,int y){
     if(x==)return y;if(y==)return x;
     if(val[x]<val[y])swap(x,y);
     ch[x][]=merge(ch[x][],y);
     if(cnt[ch[x][]]>cnt[ch[x][]])
         swap(ch[x][],ch[x][]);
     cnt[x]=cnt[ch[x][]]+;
     updata(x);
     return x;
 }
 void dfs(int x){
     for(int i=head[x];i;i=nex[i]){
         dfs(y[i]);
         rt[x]=merge(rt[x],rt[y[i]]);
         while(sum[rt[x]]>m){rt[x]=merge(ch[rt[x]][],ch[rt[x]][]);}
     }ans=max(ans,(long long)l[x]*(long long)siz[rt[x]]);
 }
 int main(){
     scanf("%d%d",&n,&m);
     for(int i=;i<=n;i++){
         scanf("%d%d%d",&fa[i],&val[i],&l[i]);
         sum[i]=val[i];rt[i]=i;siz[i]=;
         if(fa[i])init(fa[i],i);
     }
     dfs();
     printf("%lld\n",ans);
     return ;
 }