제출 #1012784

#제출 시각아이디문제언어결과실행 시간메모리
1012784hengliaoCities (BOI16_cities)C++17
100 / 100
2782 ms49844 KiB
#include<bits/stdc++.h> #include <chrono> #include <random> using namespace std; #define F first #define S second #define pb push_back #define vll vector<ll> #define pll pair<ll, ll> typedef long long ll; const ll mxN=2e5+5; const ll inf=1e18; ll n, m, k; vector<pll> adj[mxN]; vector<pair<ll, pll>> edges; ll dis[mxN][5]; ll con[5]; ll dsu[21]; ll dis2[mxN]; ll dis3[mxN]; ll find_set(ll a){ if(dsu[a]<0) return a; return dsu[a]=find_set(dsu[a]); } void unite(ll a, ll b){ ll f=find_set(a); ll s=find_set(b); if(abs(dsu[f])<abs(dsu[s])){ swap(f, s); } dsu[f]+=dsu[s]; dsu[s]=f; } bool visited[mxN]; void solve(){ cin>>n>>k>>m; for(ll i=0;i<k;i++){ cin>>con[i]; } for(ll i=0;i<m;i++){ ll u, v, w; cin>>u>>v>>w; adj[u].pb({v, w}); adj[v].pb({u, w}); edges.pb({w, {u, v}}); } sort(edges.begin(), edges.end()); if(n<=20){ ll ans=inf; for(ll mask=0;mask<(1LL<<n);mask++){ bool good=1; for(ll i=0;i<k;i++){ if((mask&(1LL<<(con[i]-1)))==0){ good=0; } } memset(dsu, -1, sizeof(dsu)); ll cur=0; for(auto &edge:edges){ ll w=edge.F; ll u=edge.S.F; ll v=edge.S.S; if((mask&(1LL<<(u-1)))==0 || (mask&(1LL<<(v-1)))==0){ continue; } if(find_set(u)!=find_set(v)){ cur+=w; unite(u, v); } } for(ll i=1;i<k;i++){ if(find_set(con[0])!=find_set(con[i])){ good=0; } } if(good) ans=min(ans, cur); } cout<<ans<<'\n'; return; } if(k==2){ //memset(visited, 0, sizeof(visited)); memset(dis, -1, sizeof(dis)); priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, con[0]}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(dis[cur.S][0]!=-1) continue; dis[cur.S][0]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } cout<<dis[con[1]][0]<<'\n'; return; } else if(k==3){ memset(dis, -1, sizeof(dis)); for(ll i=0;i<3;i++){ priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, con[i]}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(dis[cur.S][i]!=-1) continue; dis[cur.S][i]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } } ll ans=inf; for(ll i=1;i<=n;i++){ ans=min(ans, dis[i][0]+dis[i][1]+dis[i][2]); } cout<<ans<<'\n'; return; } else if(k==4){ memset(dis, -1, sizeof(dis)); for(ll i=0;i<4;i++){ priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, con[i]}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(dis[cur.S][i]!=-1) continue; dis[cur.S][i]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } } ll ans=inf; for(ll i=1;i<=n;i++){ /*cout<<i<<' '<<dis[i][0]+dis[i][1]+dis[i][2]+dis[i][3]<<'\n'; for(ll j=0;j<4;j++){ cout<<dis[i][j]<<' '; } cout<<'\n';*/ ans=min(ans, dis[i][0]+dis[i][1]+dis[i][2]+dis[i][3]); } //cout<<ans<<'\n'; for(ll ex=0;ex<4;ex++){ ll mn=inf; for(ll i=0;i<4;i++){ if(i==ex){ continue; } mn=min(mn, dis[con[i]][ex]); } for(ll mid=1;mid<=n;mid++){ ll tep=0; for(ll i=0;i<4;i++){ if(i==ex) continue; tep+=dis[mid][i]; } tep+=mn; ans=min(ans, tep); } } /*memset(tepdis, -1, sizeof(tepdis)); for(ll i=1;i<=n;i++){ priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, i}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(tepdis[cur.S][i]!=-1) continue; tepdis[cur.S][i]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } }*/ for(ll i=1;i<4;i++){ memset(dis2, -1, sizeof(dis2)); priority_queue<pll, vector<pll>, greater<pll>> pq; priority_queue<pll, vector<pll>, greater<pll>> pq2; for(ll j=1;j<=n;j++){ pq.push({dis[j][0]+dis[j][i], j}); } while(!(pq.empty() && pq2.empty())){ pll cur1={inf, inf}; pll cur2={inf, inf}; if(!pq.empty()){ cur1=pq.top(); } if(!pq2.empty()){ cur2=pq2.top(); } pll cur; if(cur1.F<cur2.F){ pq.pop(); cur.F=cur1.F; cur.S=cur1.S; } else{ pq2.pop(); cur.F=cur2.F; cur.S=cur2.S; } if(dis2[cur.S]!=-1) continue; dis2[cur.S]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq2.push({cur.F+y, x}); } } for(ll mid=1;mid<=n;mid++){ ll tep=dis2[mid]; for(ll j=1;j<4;j++){ if(j==i) continue; tep+=dis[mid][j]; } ans=min(ans, tep); } } cout<<ans<<'\n'; return; } else{ memset(dis, -1, sizeof(dis)); for(ll i=0;i<5;i++){ priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, con[i]}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(dis[cur.S][i]!=-1) continue; dis[cur.S][i]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } } ll ans=inf; for(ll i=1;i<=n;i++){ /*cout<<i<<' '<<dis[i][0]+dis[i][1]+dis[i][2]+dis[i][3]<<'\n'; for(ll j=0;j<4;j++){ cout<<dis[i][j]<<' '; } cout<<'\n';*/ ans=min(ans, dis[i][0]+dis[i][1]+dis[i][2]+dis[i][3]+dis[i][4]); } //cout<<ans<<'\n'; /*memset(tepdis, -1, sizeof(tepdis)); for(ll i=1;i<=n;i++){ priority_queue<pll, vector<pll>, greater<pll>> pq; pq.push({0, i}); while(!pq.empty()){ pll cur=pq.top(); pq.pop(); if(tepdis[cur.S][i]!=-1) continue; tepdis[cur.S][i]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq.push({cur.F+y, x}); } } }*/ for(ll i=2;i<5;i++){ memset(dis2, -1, sizeof(dis2)); priority_queue<pll, vector<pll>, greater<pll>> pq; priority_queue<pll, vector<pll>, greater<pll>> pq2; for(ll j=1;j<=n;j++){ pq.push({dis[j][1]+dis[j][i], j}); } while(!(pq.empty() && pq2.empty())){ pll cur1={inf, inf}; pll cur2={inf, inf}; if(!pq.empty()){ cur1=pq.top(); } if(!pq2.empty()){ cur2=pq2.top(); } pll cur; if(cur1.F<cur2.F){ pq.pop(); cur.F=cur1.F; cur.S=cur1.S; } else{ pq2.pop(); cur.F=cur2.F; cur.S=cur2.S; } if(dis2[cur.S]!=-1) continue; dis2[cur.S]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq2.push({cur.F+y, x}); } } memset(dis3, -1, sizeof(dis3)); for(ll j=1;j<=n;j++){ ll tep=0; for(ll k=2;k<5;k++){ if(i==k) continue; tep+=dis[j][k]; } pq.push({tep, j}); } while(!(pq.empty() && pq2.empty())){ pll cur1={inf, inf}; pll cur2={inf, inf}; if(!pq.empty()){ cur1=pq.top(); } if(!pq2.empty()){ cur2=pq2.top(); } pll cur; if(cur1.F<cur2.F){ pq.pop(); cur.F=cur1.F; cur.S=cur1.S; } else{ pq2.pop(); cur.F=cur2.F; cur.S=cur2.S; } if(dis3[cur.S]!=-1) continue; dis3[cur.S]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq2.push({cur.F+y, x}); } } for(ll j=1;j<=n;j++){ ans=min(ans, dis2[j]+dis3[j]+dis[j][0]); } } for(ll s=1;s<5;s++){ for(ll i=1;i<5;i++){ if(i==s) continue; memset(dis2, -1, sizeof(dis2)); priority_queue<pll, vector<pll>, greater<pll>> pq; priority_queue<pll, vector<pll>, greater<pll>> pq2; for(ll j=1;j<=n;j++){ pq.push({dis[j][0]+dis[j][i], j}); } while(!(pq.empty() && pq2.empty())){ pll cur1={inf, inf}; pll cur2={inf, inf}; if(!pq.empty()){ cur1=pq.top(); } if(!pq2.empty()){ cur2=pq2.top(); } pll cur; if(cur1.F<cur2.F){ pq.pop(); cur.F=cur1.F; cur.S=cur1.S; } else{ pq2.pop(); cur.F=cur2.F; cur.S=cur2.S; } if(dis2[cur.S]!=-1) continue; dis2[cur.S]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq2.push({cur.F+y, x}); } } memset(dis3, -1, sizeof(dis3)); for(ll j=1;j<=n;j++){ ll tep=0; for(ll k=1;k<5;k++){ if(k==i || k==s) continue; tep+=dis[j][k]; } pq.push({tep, j}); } while(!(pq.empty() && pq2.empty())){ pll cur1={inf, inf}; pll cur2={inf, inf}; if(!pq.empty()){ cur1=pq.top(); } if(!pq2.empty()){ cur2=pq2.top(); } pll cur; if(cur1.F<cur2.F){ pq.pop(); cur.F=cur1.F; cur.S=cur1.S; } else{ pq2.pop(); cur.F=cur2.F; cur.S=cur2.S; } if(dis3[cur.S]!=-1) continue; dis3[cur.S]=cur.F; for(auto &[x, y]:adj[cur.S]){ pq2.push({cur.F+y, x}); } } for(ll j=1;j<=n;j++){ ans=min(ans, dis2[j]+dis3[j]+dis[j][s]); } } } cout<<ans<<'\n'; return; } } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); solve(); return 0; }
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