#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path" #include "../binary_heap.hpp" #include "../../util/template.hpp" int main(){ lint n,m,s,t; cin>>n>>m>>s>>t; vector<vector<pair<lint,lint>>>g(n); rep(i,m){ lint a,b,c; cin>>a>>b>>c; g[a].emplace_back(b,c); } binary_heap<pair<lint,lint>>que; vector<binary_heap<pair<lint,lint>>::np>v(n); rep(i,n)v[i]=que.insert(make_pair(INF,i)); que.modify(v[s],make_pair(0,s)); vector<lint>from(n,-1); vector<lint>dif(n,INF); dif[s]=0; while(!que.empty()){ auto [cost,now]=que.top(); que.pop(); for(auto [e,c]:g[now]){ if(chmin(dif[e],dif[now]+c)){ from[e]=now; que.modify(v[e],make_pair(dif[e],e)); } } } if(dif[t]==INF){ cout<<-1<<endl; return 0; } lint now=t; vector<pair<lint,lint>>ans; while(1){ if(now==s)break; ans.emplace_back(from[now],now); now=from[now]; } cout<<dif[t]<<" "<<ans.size()<<endl; reverse(all(ans)); for(auto e:ans){ cout<<e.first<<" "<<e.second<<endl; } }
#line 1 "data_structure/test/LC_birary_heap.test.cpp" #define PROBLEM "https://judge.yosupo.jp/problem/shortest_path" #line 2 "data_structure/binary_heap.hpp" #include<vector> #include<algorithm> #include<functional> /** * @brief BinaryHeap */ template<typename T,typename F=std::less<T>> struct binary_heap{ int idx=1; struct node{ int idx; T val; node(int idx,T val):idx(idx),val(val){} }; using np=node*; std::vector<np>v; F comp; binary_heap(F comp):v(2,0),comp(comp){} binary_heap():v(2,0),comp(F()){} void __swap(np& s,np& t){ std::swap(s,t); std::swap(s->idx,t->idx); } void up(int k){ while(k>1&&comp(v[k]->val,v[k/2]->val)){ __swap(v[k],v[k/2]); k/=2; } } void down(int k){ while(1){ if(k*2+1<idx&&(comp(v[k*2]->val,v[k]->val)||comp(v[k*2+1]->val,v[k]->val))){ if(comp(v[k*2]->val,v[k*2+1]->val)){ __swap(v[k],v[k*2]); k=k*2; }else{ __swap(v[k],v[k*2+1]); k=k*2+1; } }else if(k*2<idx&&comp(v[k*2]->val,v[k]->val)){ __swap(v[k],v[k*2]); k=k*2; }else{ break; } } } np insert(T val){ if((int)v.size()<=idx+1)v.resize(v.size()*2,0); np res=new node(idx,val); v[idx]=res; up(idx++); return res; } T top(){ return v[1]->val; } void pop(){ __swap(v[1],v[--idx]); down(1); } int size(){ return idx-1; } bool empty(){ return idx==1; } void modify(np t,T val){ t->val=val; up(t->idx); down(t->idx); } }; #line 2 "util/template.hpp" #pragma GCC optimize("Ofast") #pragma GCC optimize("unroll-loops") #pragma GCC target("avx2") #include<bits/stdc++.h> using namespace std; struct __INIT__{__INIT__(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}}__INIT__; typedef long long lint; #define INF (1LL<<60) #define IINF (1<<30) #define EPS (1e-10) #define endl ('\n') typedef vector<lint> vec; typedef vector<vector<lint>> mat; typedef vector<vector<vector<lint>>> mat3; typedef vector<string> svec; typedef vector<vector<string>> smat; template<typename T>using V=vector<T>; template<typename T>using VV=V<V<T>>; template<typename T>inline void output(T t){bool f=0;for(auto i:t){cout<<(f?" ":"")<<i;f=1;}cout<<endl;} template<typename T>inline void output2(T t){for(auto i:t)output(i);} template<typename T>inline void debug(T t){bool f=0;for(auto i:t){cerr<<(f?" ":"")<<i;f=1;}cerr<<endl;} template<typename T>inline void debug2(T t){for(auto i:t)output(i);} #define loop(n) for(long long _=0;_<(long long)(n);++_) #define _overload4(_1,_2,_3,_4,name,...) name #define __rep(i,a) repi(i,0,a,1) #define _rep(i,a,b) repi(i,a,b,1) #define repi(i,a,b,c) for(long long i=(long long)(a);i<(long long)(b);i+=c) #define rep(...) _overload4(__VA_ARGS__,repi,_rep,__rep)(__VA_ARGS__) #define _overload3_rev(_1,_2,_3,name,...) name #define _rep_rev(i,a) repi_rev(i,0,a) #define repi_rev(i,a,b) for(long long i=(long long)(b)-1;i>=(long long)(a);--i) #define rrep(...) _overload3_rev(__VA_ARGS__,repi_rev,_rep_rev)(__VA_ARGS__) // #define rep(i,...) for(auto i:range(__VA_ARGS__)) // #define rrep(i,...) for(auto i:reversed(range(__VA_ARGS__))) // #define repi(i,a,b) for(lint i=lint(a);i<(lint)(b);++i) // #define rrepi(i,a,b) for(lint i=lint(b)-1;i>=lint(a);--i) // #define irep(i) for(lint i=0;;++i) // inline vector<long long> range(long long n){if(n<=0)return vector<long long>();vector<long long>v(n);iota(v.begin(),v.end(),0LL);return v;} // inline vector<long long> range(long long a,long long b){if(b<=a)return vector<long long>();vector<long long>v(b-a);iota(v.begin(),v.end(),a);return v;} // inline vector<long long> range(long long a,long long b,long long c){if((b-a+c-1)/c<=0)return vector<long long>();vector<long long>v((b-a+c-1)/c);for(int i=0;i<(int)v.size();++i)v[i]=i?v[i-1]+c:a;return v;} // template<typename T>inline T reversed(T v){reverse(v.begin(),v.end());return v;} #define all(n) begin(n),end(n) template<typename T,typename E>bool chmin(T& s,const E& t){bool res=s>t;s=min<T>(s,t);return res;} template<typename T,typename E>bool chmax(T& s,const E& t){bool res=s<t;s=max<T>(s,t);return res;} const vector<lint> dx={1,0,-1,0,1,1,-1,-1}; const vector<lint> dy={0,1,0,-1,1,-1,1,-1}; #define SUM(v) accumulate(all(v),0LL) template<typename T,typename ...Args>auto make_vector(T x,int arg,Args ...args){if constexpr(sizeof...(args)==0)return vector<T>(arg,x);else return vector(arg,make_vector<T>(x,args...));} #define extrep(v,...) for(auto v:__MAKE_MAT__({__VA_ARGS__})) #define bit(n,a) ((n>>a)&1) vector<vector<long long>> __MAKE_MAT__(vector<long long> v){if(v.empty())return vector<vector<long long>>(1,vector<long long>());long long n=v.back();v.pop_back();vector<vector<long long>> ret;vector<vector<long long>> tmp=__MAKE_MAT__(v);for(auto e:tmp)for(long long i=0;i<n;++i){ret.push_back(e);ret.back().push_back(i);}return ret;} using graph=vector<vector<int>>; template<typename T>using graph_w=vector<vector<pair<int,T>>>; template<typename T,typename E>ostream& operator<<(ostream& out,pair<T,E>v){out<<"("<<v.first<<","<<v.second<<")";return out;} constexpr inline long long powll(long long a,long long b){long long res=1;while(b--)res*=a;return res;} #line 4 "data_structure/test/LC_birary_heap.test.cpp" int main(){ lint n,m,s,t; cin>>n>>m>>s>>t; vector<vector<pair<lint,lint>>>g(n); rep(i,m){ lint a,b,c; cin>>a>>b>>c; g[a].emplace_back(b,c); } binary_heap<pair<lint,lint>>que; vector<binary_heap<pair<lint,lint>>::np>v(n); rep(i,n)v[i]=que.insert(make_pair(INF,i)); que.modify(v[s],make_pair(0,s)); vector<lint>from(n,-1); vector<lint>dif(n,INF); dif[s]=0; while(!que.empty()){ auto [cost,now]=que.top(); que.pop(); for(auto [e,c]:g[now]){ if(chmin(dif[e],dif[now]+c)){ from[e]=now; que.modify(v[e],make_pair(dif[e],e)); } } } if(dif[t]==INF){ cout<<-1<<endl; return 0; } lint now=t; vector<pair<lint,lint>>ans; while(1){ if(now==s)break; ans.emplace_back(from[now],now); now=from[now]; } cout<<dif[t]<<" "<<ans.size()<<endl; reverse(all(ans)); for(auto e:ans){ cout<<e.first<<" "<<e.second<<endl; } }