제출 #1236462

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1236462		Geforgs	Commuter Pass (JOI18_commuter_pass)	C++20	100 / 100	365 ms	22220 KiB

commuter_pass

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <unordered_map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
#define ll long long
#define ld long double
#define inf (ll)(2*1e18)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define pb push_back
#define endl "\n"
using namespace std;

void Dijkstra(ll start, vector<vector<pair<ll, ll>>>& a, vector<ll>& dis){
    set<pair<ll, ll>> s;
    dis[start] = 0;
    s.insert({0, start});
    while(!s.empty()){
        auto [val, x] = *s.begin();
        s.erase(s.begin());
        for(auto [el, w]: a[x]){
            if(dis[el] > val + w){
                s.erase({dis[el], el});
                dis[el] = val + w;
                s.insert({dis[el], el});
            }
        }
    }
}

void solve(){
    ll n, m, i, start, finish, u, v, x, y, w;
    cin>>n>>m;
    cin>>start>>finish;
    cin>>u>>v;
    --start;
    --finish;
    --u;
    --v;
    vector<vector<pair<ll, ll>>> a(n);
    vector<ll> b(n, inf);
    vector<ll> b2(n, inf);
    vector<ll> c(n, inf);
    vector<ll> c2(n, inf);
    vector<ll> dis(n, inf);
    for(i=0;i<m;++i){
        cin>>x>>y>>w;
        --x;
        --y;
        a[x].pb({y, w});
        a[y].pb({x, w});
    }
    Dijkstra(u, a, b);
    Dijkstra(v, a, c);
    set<pair<ll, ll>> s;
    dis[start] = 0;
    s.insert({0, start});
    b2[start] = b[start];
    c2[start] = c[start];
    while(!s.empty()){
        x = s.begin()->second;
        s.erase(s.begin());
        for(auto el: a[x]){
            y = el.first;
            w = el.second;
            if(dis[y] > dis[x] + w){
                b2[y] = min(b[y], b2[x]);
                c2[y] = min(c[y], c2[x]);
                s.erase({dis[y], y});
                dis[y] = dis[x] + w;
                s.insert({dis[y], y});
            }else if(dis[y] == dis[x] + w){
                if(b2[y] + c2[y] > min(b[y], b2[x]) + min(c[y], c2[x])){
                    b2[y] = min(b[y], b2[x]);
                    c2[y] = min(c[y], c2[x]);
                }
            }
        }
    }
    cout<<min(b2[finish] + c2[finish], b[v])<<endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    srand(time(nullptr));
    ll t=1;
//    cin>>t;
    for(;t>0;--t){
        solve();
    }
    return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45