제출 #524797

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
524797		Netr	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	452 ms	25680 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pi;
 
#ifdef DEBUG
#define D(x...) printf(x);
#else
#define D(x...)
#endif
 
const ll MAXN = 1e5 + 5;
const ll INF = 1ll<<62;
 
ll N,M,S,T,U,V,UD[MAXN],VD[MAXN],SD[MAXN],vis[MAXN],ans;
pi dp[MAXN];
 
vector<pi> edge[MAXN];
 
pi dfs(int i){
    D("%d: ud,vd = %d, %d\n", i, UD[i], VD[i])
    if(i == S) return {UD[S],VD[S]};
    if(vis[i]) return dp[i];
    vis[i] = 1;
    ll udist = INF/2, vdist = INF/2;
    for(auto e : edge[i]){
        if(SD[e.first] + e.second == SD[i]){
            auto res = dfs(e.first);
            if(min(UD[i], res.first) + min(VD[i], res.second) < udist + vdist){
                udist = min(UD[i], res.first);
                vdist = min(VD[i], res.second);
            }
        }
    }
    dp[i] = {udist, vdist};
    return {udist, vdist};
}
 
void djikstras(int src, ll *d, ll s){
    priority_queue<pi, vector<pi>, greater<pi>> pq;
    fill(d, d+s+1, INF);
    pq.push({d[src] = 0, src});
    while(!pq.empty()){
        auto t = pq.top(); pq.pop();
        if(d[t.second] != t.first) continue;
        for(auto e : edge[t.second]){
            if(d[t.second] + e.second < d[e.first]){
                pq.push({d[e.first] = d[t.second] + e.second, e.first});
            }
        }
    }
}
 
int main(){
    cin >> N >> M >> S >> T >> U >> V;
    for(int i = 0; i < M; i++){
        ll ai, bi, ci;
        cin >> ai >> bi >> ci;
        edge[bi].push_back({ai, ci});
        edge[ai].push_back({bi, ci});
    }
    djikstras(S, SD, N);
    djikstras(U, UD, N);
    djikstras(V, VD, N);
    ans = UD[V];
    auto res = dfs(T);
    ans = min(ans, res.first + res.second);
    cout << ans << "\n";
}

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