結果
問題 | No.1212 Second Path |
ユーザー |
|
提出日時 | 2020-08-30 15:59:21 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 1,073 ms / 3,000 ms |
コード長 | 4,804 bytes |
コンパイル時間 | 3,625 ms |
コンパイル使用メモリ | 212,000 KB |
最終ジャッジ日時 | 2025-01-13 23:17:24 |
ジャッジサーバーID (参考情報) |
judge1 / judge4 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 45 |
ソースコード
#include <bits/stdc++.h>using namespace std;#define rep(i, n) for(long long i=0;i<(long long)(n);i++)#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)#define all(a) a.begin(),a.end()#define pb emplace_back#define eb emplace_back#define lb(v,k) (lower_bound(all(v),k)-v.begin())#define ub(v,k) (upper_bound(all(v),k)-v.begin())#define fi first#define se second#define pi M_PI#define PQ(T) priority_queue<T>#define SPQ(T) priority_queue<T,vector<T>,greater<T>>#define dame(a) {out(a);return 0;}#define decimal cout<<fixed<<setprecision(15);#define dupli(a) {sort(all(a));a.erase(unique(all(a)),a.end());}typedef long long ll;typedef pair<ll,ll> P;typedef tuple<ll,ll,ll> PP;typedef tuple<ll,ll,ll,ll> PPP;typedef multiset<ll> S;using vi=vector<ll>;using vvi=vector<vi>;using vvvi=vector<vvi>;using vvvvi=vector<vvvi>;using vp=vector<P>;using vvp=vector<vp>;using vb=vector<bool>;using vvb=vector<vb>;const ll inf=1001001001001001001;const ll INF=1001001001;const ll mod=1000000007;const double eps=1e-10;template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}template<class T> void out(T a){cout<<a<<'\n';}template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}template<class T> void yesno(T b){if(b)out("yes");else out("no");}template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}template<class T> void noyes(T b){if(b)out("no");else out("yes");}template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}vvp g;vi sz,par,id,head,dep,mi,m,M;vvp aa;ll num;ll dfs(int i,int p){if(g[i][0].fi==p)swap(g[i][0],g[i].back());for(auto&to:g[i]){if(to.fi==p)continue;sz[i]+=dfs(to.fi,i);if(sz[to.fi]>sz[g[i][0].fi])swap(to,g[i][0]);}return sz[i];}void dfs1(int i,int p){par[i]=p;id[i]=num++;vi v;for(auto to:g[i]){if(to.fi==p)continue;v.pb(to.se);aa[i].pb(to.se,to.fi);chmin(mi[i],to.se);if(to==g[i][0])head[to.fi]=head[i];dep[to.fi]=dep[i]+to.se;M[to.fi]=to.se;dfs1(to.fi,i);}sort(all(v));sort(all(aa[i]));if(v.size()>1){for(auto to:g[i])if(to.fi!=p){if(v[0]==to.se)m[id[to.fi]]=v[1];else m[id[to.fi]]=v[0];}}}ll lca(ll a,ll b){while(head[a]!=head[b]){if(dep[head[a]]>dep[head[b]])a=par[head[a]];else b=par[head[b]];}if(dep[a]<dep[b])return a;return b;}vi seg;ll N;void initseg(vi v){N=1;while(N<v.size())N*=2;seg=vi(N*2-1,inf);rep(i,v.size())seg[i+N-1]=v[i];for(int i=N-2;i>=0;i--)seg[i]=min(seg[i*2+1],seg[i*2+2]);}ll getmi(ll a,ll b,ll k,ll l,ll r){if(r<=a||b<=l)return inf;if(a<=l&&r<=b)return seg[k];ll c1=getmi(a,b,k*2+1,l,(l+r)/2);ll c2=getmi(a,b,k*2+2,(l+r)/2,r);return min(c1,c2);}ll do_edge(int a,int b){ll res=inf;while(head[a]!=head[b]){if(par[head[b]]!=a)chmin(res,getmi(id[head[b]],id[b]+1,0,0,N));else chmin(res,getmi(id[head[b]]+1,id[b]+1,0,0,N));b=par[head[b]];}chmin(res,getmi(id[a]+2,id[b]+1,0,0,N));return res;}void init(ll n){sz=vi(n,1);par=vi(n);id=vi(n);head=vi(n);dep=vi(n);mi=vi(n,inf);m=vi(n,inf);M=vi(n,inf);aa=vvp(n);rep(i,n)head[i]=i;num=0;dfs(0,-1);dfs1(0,-1);initseg(m);}int main(){ll n;cin>>n;g=vvp(n);rep(i,n-1){ll a,b,c;cin>>a>>b>>c;a--;b--;g[a].pb(b,c);g[b].pb(a,c);}init(n);ll q;cin>>q;rep(qq,q){ll a,b;cin>>a>>b;a--;b--;ll l=lca(a,b);ll ans=min(do_edge(l,a),do_edge(l,b));if(a!=l)chmin(ans,mi[a]);if(b!=l)chmin(ans,mi[b]);chmin(ans,M[l]);for(auto p:aa[l]){if(lca(p.se,a)==l&&lca(p.se,b)==l){chmin(ans,p.fi);break;}}if(ans!=inf)out(dep[a]+dep[b]-dep[l]*2+ans*2);else out(-1);}}