题解：最短路模板题
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#include <cstdio>#include <utilily> #include <cstring> #include <queue> using
namespace std; const
int N=20005; const
int INF=9999999; typedef
pair<int,int>seg; priority_queue<seg>,vector<seg>,greater<seg> >q; int
d[N],head[N],u[N],v[N],w[N],next[N],n,m,a,b,c; bool
vis[N]; void
build(){ memset(head,-1,sizeof(head)); for(int
e=1;e<=m;e++){ scanf("%d%d%d",&u[e],&v[e],&w[e]); u[e+m]=v[e]; v[e+m]=u[e]; w[e+m]=w[e]; next[e]=head[u[e]]; head[u[e]]=e; next[e+m]=head[u[e+m]]; head[u[e+m]]=e+m; } } void
Dijkstra(int
src){ memset(vis,0,sizeof(vis)); for(int
i=1;i<=n;i++) d[i]=INF; d[src]=0; q.push(make_pair(d[src],src)); while(!q.empty()){ seg now=q.top(); q.pop(); int
x=now.second; if(vis[x]) continue; vis[x]=true; for(int
e=head[x];e!=-1;e=next[e]) if(d[v[e]]>d[x]+w[e]){ d[v[e]]=d[x]+w[e]; q.push(make_pair(d[v[e]],v[e])); } } } int
main(){ while(~scanf("%d%d",&n,&m)&&n+m){build();Dijkstra(1);printf("%d\n",d[n]);} return
0; } |
原文：http://www.cnblogs.com/forever97/p/3608643.html