제출 #874308

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
874308		tsumondai	Commuter Pass (JOI18_commuter_pass)	C++14	15 / 100	2065 ms	91008 KiB

commuter_pass

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define __TIME  (1.0 * clock() / CLOCKS_PER_SEC)

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
 
const int N = 1e6 + 5;
 
const int oo = 1e18, mod = 1e9 + 7;
 
int n, m, k, points[5], vis[N], dpU[N], dpV[N], ans;

vector<ii> adj[N];
vector<int> dag[N];

int dist[N][5];

bool mini(int &a, const int b) {
	if (a>b) {
		a=b; return true;
	} else {
		return false;
	}
}

bool maxi(int &a, const int b) {
	if (a<b) {
		a=b;
		return true;
	} else {
		return false;
	}
}

void dfs(int u, int par) {
	for (auto v: dag[u]) {
		if (v==par) continue;
		dfs(v,u);
		mini(dpU[u], min(dpU[v], dist[v][3]));
		mini(dpV[u], min(dpV[v], dist[v][4]));
	}
	mini(ans, dpU[u]+dist[u][4]);
	mini(ans, dpV[u]+dist[u][3]);
}

void dijkstra(int s) {
	foru(i,1,n) dist[i][s]=oo;
    priority_queue <pair <long long, int>> pq;
    pq.push(make_pair(dist[points[s]][s] = 0, points[s]));
    while (!pq.empty()) {
        //auto [du, u] = pq.top(); pq.pop();
        pair<long long, long long> tmp=pq.top(); pq.pop();
        long long du=tmp.first, u=tmp.second;
 
        du = -du;
        if (du != dist[u][s]) continue;
       /* for (auto [w, v]: adj[u]) if (dist[v] > du + w) {
            dist[v] = du + w;
            pq.push(make_pair(-dist[v], v));
        }*/
        for (pair<long long, long long> nxt: adj[u]) if (dist[nxt.second][s] > du + nxt.first) {
            dist[nxt.second][s] = du + nxt.first;
            pq.push(make_pair(-dist[nxt.second][s], nxt.second));
        }
    }
}

void process() {
	cin >> n >> m;// 1 2 3 4
	foru(i,1,4) cin >> points[i];
	foru(i,1,m) {
		int u, v, c;
		cin >> u >> v >> c;
		adj[u].pb({c,v});
		adj[v].pb({c,u});
	}

	foru(i,1,4) dijkstra(i);

	foru(x,1,n) {
		for (auto tmp: adj[x]) {
			int y=tmp.se, w=tmp.fi;
			if (dist[x][1] + w + dist[y][2] == dist[points[2]][1]) {
				dag[x].pb(y);
			}
		}
	}

	ans=dist[points[3]][4];
	memset(dpU, 0x3f, sizeof(dpU));
	memset(dpV, 0x3f, sizeof(dpV));
	dfs(points[1], 0);
	cout << ans;
    return;
}

signed main() {
    cin.tie(0)->sync_with_stdio(false);
    //freopen(".inp", "r", stdin);
    //freopen(".out", "w", stdout);
    process();
    cerr << "Time elapsed: " << __TIME << " s.\n";
    return 0;
}

• Subtask 1: 0 / 16
• Subtask 2: 15 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 45