luogu P3238 [HNOI2014]道路堵塞
作者:互联网
代码:
#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<deque>
#include<queue>
using namespace std;
deque <int> q;
priority_queue <pair<int,int> > Q;
const int N=1000009,INF=1<<30;
int n,m,L,dis[N],inq[N],x[N],y[N],z[N],l[N],cnt,del[N],head[N],D[N],rev[N];
struct Edge
{
int nxt,to,w;
}g[N*2];
void add(int from,int to,int w)
{
g[++cnt].nxt=head[from];
g[cnt].to=to;
g[cnt].w=w;
head[from]=cnt;
}
void SPFA(int S)
{
q.push_front(S);
while(!q.empty())
{
int x=q.front();q.pop_front();
inq[x]=0;
for (int i=head[x];i;i=g[i].nxt)
{
int v=g[i].to;
if(dis[v]<=dis[x]+g[i].w||del[i])
continue;
dis[v]=dis[x]+g[i].w;
if(!inq[v])
{
inq[v]=1;
if(!q.empty()&&dis[q.front()]>=dis[v])
q.push_front(v);
else
q.push_back(v);
}
if(D[v]!=0||v==n)
Q.push(make_pair(-(dis[v]+D[v]),v));
}
}
}
void init()
{
scanf("%d %d %d",&n,&m,&L);
for (int i=1;i<=m;i++)
scanf("%d %d %d",&x[i],&y[i],&z[i]),add(x[i],y[i],z[i]);
for (int i=1;i<=L;i++)
scanf("%d",&l[i]),del[l[i]]=1,rev[x[l[i]]]=i;
rev[n]=INF;
for (int i=L;i>=1;i--)
D[x[l[i]]]=D[y[l[i]]]+z[l[i]];
}
void work()
{
for (int i=1;i<=n;i++)
dis[i]=INF;
dis[1]=0;
SPFA(1);
printf("%d\n",Q.empty()?-1:-Q.top().first);
for (int i=1;i<L;i++)
{
del[l[i]]=0;
SPFA(x[l[i]]);
while(!Q.empty()&&rev[Q.top().second]<=i+1)
Q.pop();
printf("%d\n",Q.empty()?-1:-Q.top().first);
}
}
int main()
{
init();
work();
return 0;
}
标签:include,int,luogu,void,back,HNOI2014,push,P3238,dis 来源: https://www.cnblogs.com/With-penguin/p/12839141.html