洛谷 1113 杂务 拓扑排序（裸）

题目：
https://www.luogu.org/problem/show?pid=1113

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>#include<queue>using namespace std;const int MAXN=30001;int tot,fst[MAXN],nxt[MAXN],dis[MAXN],n,ru[MAXN],lu[MAXN],vis[MAXN];struct hh{    int from,to;}ma[MAXN<<1];queue<int>q;void build(int f,int t){    tot++;    ma[tot]=(hh){f,t};    nxt[tot]=fst[f];    fst[f]=tot;    return;}void bfs(){    while(!q.empty())    {        int x=q.front();        q.pop();        for(int i=fst[x];i;i=nxt[i])        {            int v=ma[i].to;            ru[v]--;            lu[v]=max(lu[v],lu[x]+dis[v]);            if(!ru[v]) q.push(v);        }    }    return;}void solve(){    int x,y,z,ans=0;    cin>>n;    for(int i=1;i<=n;i++)    {        scanf("%d%d",&x,&y);        dis[x]=y;        while(~scanf("%d",&y))        {            if(y==0) break;            build(y,x),ru[x]++;        }    }    for(int i=1;i<=n;i++) if(!ru[i]) q.push(i),lu[i]=dis[i];    bfs();    for(int i=1;i<=n;i++) ans=max(ans,lu[i]);    cout<<ans;}int main(){    solve();    return 0;}