【SDOI2010】大陆争霸

题面

https://www.luogu.org/problem/P2446

题解

// luogu-judger-enable-o2
#include<cstdio>
#include<iostream>
#include<cstring>
#include<vector>
#include<queue>
#define LL long long
#define ri register int
#define N 3050
using namespace std;

int n,m;
vector<int> to[N],len[N];
vector<int> fa[N];
LL dis[N],d[N];
bool vis[N];
int cnt[N],tot[N];


void add_edge(int z,int y,int x) {
  to[z].push_back(y); len[z].push_back(x);
}

struct node {
  int x; LL d;
  bool operator < (const node &rhs) const {
    return d>rhs.d;
  }
};
priority_queue<node> q;

LL dij() {
  memset(dis,0x3f,sizeof(dis));
  dis[1]=0;
  q.push((node){1,0});
  while (!q.empty()) {
    int x=q.top().x; q.pop();
    if (vis[x]) continue;
    vis[x]=1;
    for (ri i=0;i<fa[x].size();i++) {
      dis[fa[x][i]]=max(dis[x],dis[fa[x][i]]);
      cnt[fa[x][i]]++;
      if (cnt[fa[x][i]]==tot[fa[x][i]]) {
        q.push((node){fa[x][i],dis[fa[x][i]]});
      }
    }
    for (ri i=0;i<to[x].size();i++) {
      int y=to[x][i];
      if (dis[y]>dis[x]+len[x][i]) {
        dis[y]=dis[x]+len[x][i];
        if (cnt[y]==tot[y]) q.push((node){y,dis[y]});
      }
    }
  }
  return dis[n];
}

int main() {
  int a,b,c;
  scanf("%d %d",&n,&m);
  for (ri i=1;i<=m;i++) {
    scanf("%d %d %d",&a,&b,&c);
    add_edge(a,b,c);
  }
  for (ri i=1;i<=n;i++) {
    scanf("%d",&tot[i]);
    for (ri j=1;j<=tot[i];j++) {
      scanf("%d",&b);
      fa[b].push_back(i);
    }
  }
  cout<<dij()<<endl;
}