test/yosupo_Shortest_Path.test.cpp

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Last update: 2023-04-05 23:10:22+09:00
Problem: https://judge.yosupo.jp/problem/shortest_path

Depends on

Code

#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"

#include "../template.hpp"

#include "../Graph/Dijkstra.hpp"

signed main(){
    int n,m,s,t;cin>>n>>m>>s>>t;
    Dijkstra<ll> d(n);
    rep(i,m){
        int u,v;ll c;cin>>u>>v>>c;
        d.add_edge(u,v,c);
    }
    d.build(s);
    auto p=d.get_path(t);
    if(p.empty()) cout<<-1<<endl;
    else{
        cout<<d[t]<<" "<<(int)p.size()-1<<endl;
        int k=p[0];
        for(int i=1;i<(int)p.size();i++){
            cout<<k<<" "<<p[i]<<endl;
            k=p[i];
        }
    }
    return 0;
}

#line 1 "test/yosupo_Shortest_Path.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"

#line 1 "template.hpp"
#include<bits/stdc++.h>
using namespace std;
#define ALL(x) begin(x),end(x)
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}
template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}

#line 4 "test/yosupo_Shortest_Path.test.cpp"

#line 1 "Graph/Dijkstra.hpp"
template<typename T>
struct Dijkstra{
    const T TINF=numeric_limits<T>::max();
    using P=pair<T,int>;
    int n;
    vector<vector<P>> G;
    vector<T> d;
    vector<int> prev;
  
    Dijkstra(int n):n(n),G(vector<vector<P>>(n)){}
    void init(){
        d.assign(n,TINF);
        prev.assign(n,-1);
    }
    void add_edge(int s,int t,T cost){
        G[s].push_back(P(cost,t));
    }
    void build(int s){
        init();
        d[s]=0;
        priority_queue<P,vector<P>,greater<P>> q;
        q.push(P(d[s],s));
        while(!q.empty()){
            P p=q.top();q.pop();
            int v=p.second;
            if(d[v]<p.first) continue;
            for(auto e:G[v]){
                int u=e.second;
                T cost=e.first;
                if(d[u]>d[v]+e.first){
                    d[u]=d[v]+cost;
                    prev[u]=v;
                    q.push(P(d[u],u));
                }
            }
        }
    }
 
    T operator[](const int &p)const{
        return d[p];
    }
 
    vector<int> get_path(int g){
        vector<int> ret;
        if(d[g]==TINF) return ret;
        for(;g!=-1;g=prev[g]){
            ret.push_back(g);
        }
        reverse(ret.begin(),ret.end());
        return ret;
    }
};
#line 6 "test/yosupo_Shortest_Path.test.cpp"

signed main(){
    int n,m,s,t;cin>>n>>m>>s>>t;
    Dijkstra<ll> d(n);
    rep(i,m){
        int u,v;ll c;cin>>u>>v>>c;
        d.add_edge(u,v,c);
    }
    d.build(s);
    auto p=d.get_path(t);
    if(p.empty()) cout<<-1<<endl;
    else{
        cout<<d[t]<<" "<<(int)p.size()-1<<endl;
        int k=p[0];
        for(int i=1;i<(int)p.size();i++){
            cout<<k<<" "<<p[i]<<endl;
            k=p[i];
        }
    }
    return 0;
}