제출 #1142880

#제출 시각아이디문제언어결과실행 시간메모리
1142880AmirMakaMCommuter Pass (JOI18_commuter_pass)C++20
100 / 100
728 ms23740 KiB
#include <bits/stdc++.h>
using namespace std;
#define ull unsigned long long
#define ll long long
#define ld long double
#define pb push_back
#define f first
#define s second 
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define pii pair<int,int> 
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define pdd pair<double,double>
#define mp make_pair   
#define AmirMakaM ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
// solve it
const ull SEED = chrono::steady_clock::now().time_since_epoch().count();
mt19937_64 mrand(SEED);
ull rnd(ull x = ~(0ull)) {return mrand() % x;} 
const ll MOD = 998244353;
const ll INF = 1e16+20;
const int inf = 1e9 + 7;
const ll N = 1e5+5;
const ll M = 2e3+1;
const double pi = 2*acos(0.0);
const int dx[] = {1,-1,0,0}, dy[] = {0,0,1,-1};

int n, m;
vector<pll> g[N];
ll d[N][5];

void dj(int s, int x) {
    for(int i=1; i<=n; i++) d[i][x] = INF;
    set<pll> best;
    d[s][x] = 0;
    best.insert({d[s][x],s});

    while(!best.empty()) {
        auto curr = *best.begin();
        best.erase(curr);
        int v = curr.s;

        for(auto it:g[v]) {
            if(d[it.f][x] <= d[v][x] + it.s) continue;
            best.erase({d[it.f][x],it.f});
            d[it.f][x] = d[v][x] + it.s;
            best.insert({d[it.f][x],it.f});
        }
    }
}

void solve() {
    cin >> n >> m;
    int s, t, u, v;
    cin >> s >> t >> u >> v;

    for(ll i=1, x, y, s; i<=m; i++) {
        cin >> x >> y >> s;
        g[x].pb({y,s});
        g[y].pb({x,s});
    }

    dj(s,0), dj(t,1);
    dj(u,2), dj(v,3);
    ll ans = d[v][2];

    bool used[n+1];
    pll dp[n+1];
    for(int i=1; i<=n; i++) {
        used[i] = 0;
        dp[i] = {d[i][2],d[i][3]};
    }

    set<pll> q;
    q.insert({d[s][0],s});
    while(!q.empty()) {
        auto curr = *q.begin();
        q.erase(curr);
        ll z = curr.s;
        used[z] = 1;

        for(auto it:g[z]) {
            int to = it.f;
            ll w = it.s;
            if(d[to][0] + d[to][1] != d[t][0]) continue;
            dp[to] = {min(dp[to].f,dp[z].f),min(dp[to].s,dp[z].s)};
            if(used[to]) continue;
            ans = min(ans,min(d[to][3]+dp[z].f,d[to][2]+dp[z].s));
            q.insert({d[to][0],to});
        }
    }

    cout << ans;
}

int main() {
    AmirMakaM;
    srand(SEED);
    //freopen("bulk.in", "r", stdin);
    //freopen("bulk.out", "w", stdout);
    int ttt = 1;
    //cin >> ttt;
    while(ttt--) {
        solve();
    }
    return 0;
}
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