제출 #1093052

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1093052		PagodePaiva	Commuter Pass (JOI18_commuter_pass)	C++17	100 / 100	327 ms	30396 KiB

commuter_pass

#include<bits/stdc++.h>
#define inf 1e16
#define int long long

using namespace std;

const int N = 100010;
int dists[N], distt[N], dist[N][4];
vector <pair <int, int>> g[N];
int s, t, start, endd;

int32_t main(){
    int n, m;
    cin >> n >> m;
    cin >> s >> t;
    cin >> start >> endd;
    for(int i = 0;i < m;i++){
        int a, b, w;
        cin >> a >> b >> w;
        g[a].push_back({b, w});
        g[b].push_back({a, w});
    }
    priority_queue <pair <int, int>> pq;
    for(int i = 1;i <= n;i++){
        dists[i] = distt[i] = inf;
        dist[i][0] = dist[i][1] = dist[i][2] = dist[i][3] = inf;
    }
    dists[s] = 0;
    pq.push({0, s});
    while(!pq.empty()){
        auto [d, v] = pq.top();
        pq.pop();
        if(-d != dists[v]) continue;
        for(auto [x, w] : g[v]){
            if(dists[x] > dists[v] + w){
                dists[x] = dists[v] + w;
                pq.push({-dists[x], x});
            }
        }
    }
    distt[t] = 0;
    pq.push({0, t});
    while(!pq.empty()){
        auto [d, v] = pq.top();
        pq.pop();
        if(-d != distt[v]) continue;
        for(auto [x, w] : g[v]){
            if(distt[x] > distt[v] + w){
                distt[x] = distt[v] + w;
                pq.push({-distt[x], x});
            }
        }
    }
    dist[start][0] = 0;
    priority_queue <array <int, 3>> pqq;
    pqq.push({0, start, 0});
    while(!pqq.empty()){
        auto [d, v, flag] = pqq.top();
        pqq.pop();
        if(-d != dist[v][flag]) continue;
        if(flag == 0){
            if(dist[v][flag+1] > dist[v][flag]){
                dist[v][flag+1] = dist[v][flag];
                pqq.push({-dist[v][flag+1], v, flag+1});
            }
            if(dist[v][flag+2] > dist[v][flag]){
                dist[v][flag+2] = dist[v][flag];
                pqq.push({-dist[v][flag+2], v, flag+2});
            }
        }
        if(flag == 1){
            if(dist[v][flag+2] > dist[v][flag]){
                dist[v][flag+2] = dist[v][flag];
                pqq.push({-dist[v][flag+2], v, flag+2});
            }
        }
        if(flag == 2){
            if(dist[v][flag+1] > dist[v][flag]){
                dist[v][flag+1] = dist[v][flag];
                pqq.push({-dist[v][flag+1], v, flag+1});
            }
        }
        for(auto [x, w] : g[v]){
            if(flag == 0){
                if(dist[x][0] > dist[v][0] + w){
                    dist[x][0] = dist[v][0] + w;
                    pqq.push({-dist[x][0], x, 0});
                }
            }
            else if(flag == 1){
                if(dists[v] + distt[x] + w == dists[t]){
                    if(dist[x][1] > dist[v][1]){
                        dist[x][1] = dist[v][1];
                        pqq.push({-dist[x][1], x, 1});
                    }
                }
            }
            else if(flag == 2){
                if(distt[v] + dists[x] + w == dists[t]){
                    if(dist[x][2] > dist[v][2]){
                        dist[x][2] = dist[v][2];
                        pqq.push({-dist[x][2], x, 2});
                    }
                }
            }
            else{
                if(dist[x][3] > dist[v][3] + w){
                    dist[x][3] = dist[v][3] + w;
                    pqq.push({-dist[x][3], x, 3});
                }
            }
        }
    }
    cout << dist[endd][3] << '\n';
}

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