# 题解

#include<bits/stdc++.h>
using namespace std;
#define re register
#define ll long long
#define in inline
#define get getchar()
{
int t=0; char ch=get;
while(ch<'0' || ch>'9') ch=get;
while(ch<='9' && ch>='0') t=t*10+ch-'0', ch=get;
return t;
}
const int _=4e5+5;
struct edge{
int to,ne,w,fr;
}e[_],ft[_];//ft记录非树边
int vis[_],cnt,dis[_],father[_],from[_],tot,h[_],n,m,ans[_]; //from记录最短路树中父亲,cnt是非树边的数量
in void add(int x,int y,int z)
{
e[++tot].ne=h[x],e[tot].fr=x,e[tot].w=z,e[tot].to=y,h[x]=tot;
}
in void dijkstra() //dijkstra
{
priority_queue<pair<int ,int> >q;
memset(dis,0x3f,sizeof(dis));
dis[1]=0;
q.push(make_pair(0,1));
while(!q.empty())
{
int u=q.top().second;q.pop();
if(vis[u]) continue;
vis[u]=1;
for(re int i=h[u];i;i=e[i].ne)
{
int v=e[i].to;
if(dis[v]>dis[u]+e[i].w)
{
from[v]=u;
dis[v]=dis[u]+e[i].w;
q.push(make_pair(-dis[v],v));
}
}
}
return ;
}
in int cmp(edge x,edge y)
{
return x.w<y.w;
}
in int find(int x)
{
if(father[x]==x) return x;
father[x]=find(father[x]);
return father[x];
}
int main()
{
for(re int i=1;i<=m;i++)
{
}
dijkstra();
for(re int i=1;i<=m*2;i+=2) //找非树边
{
int u=e[i].fr,v=e[i].to;
if(from[u]==v||from[v]==u) continue;
ft[++cnt].to=v,ft[cnt].fr=u,ft[cnt].w=dis[u]+e[i].w+dis[v];
}
sort(ft+1,ft+1+cnt,cmp);
for(re int i=1;i<=n;i++) father[i]=i;
memset(ans,0,sizeof(ans));
for(re int i=1;i<=cnt;i++) //枚举更新非树边求答案
{
int u=find(ft[i].fr),v=find(ft[i].to);
while(u!=v)
{
if(dis[u]<dis[v]) swap(u,v);
ans[u]=ft[i].w-dis[u];
father[u]=from[u];
u=find(u);
}
}
for(re int i=2;i<=n;i++)cout<<(ans[i]==0?-1:ans[i])<<endl;
}


posted @ 2019-10-10 18:43  yzhx  阅读(198)  评论(1编辑  收藏  举报