oj.uz

Submission #410470

# Submission time Handle Problem Language Result Execution time Memory
410470 2021-05-22T18:16:21 Z ngpin04 Olympic Bus (JOI20_ho_t4) C++14
32 / 100
 60 ms 4764 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define int long long 
using namespace std;
const int N = 205;
const int M = 5e4 + 5; 
const int oo = 1e18;
 
vector <int> adj[N];
vector <int> newadj[N];
 
pair <int, int> edge[M];
 
int dis[N][N];
int d[N];
int f[M];
int g[M];
int par[N];
int cost[M];
int revcost[M];
int n,m;
 
bool vis[N];
bool flag[M];
bool mark[N];
 
template <typename T> 
bool mini(T &a, T b) {
	if (a > b) {
		a = b;
		return true;
	}
	return false;
}
 
void dfs(int u, int p) {
	par[u] = p;
	for (int id : newadj[u]) {
		int v = edge[id].se;
		d[v] = d[u] + 1;
		dfs(v, id);
	} 
}
 
void solve(int f[], int s, int t) {
	for (int i = 1; i <= n; i++) {
		vis[i] = mark[i] = false;
		newadj[i].clear();
	}
 
	for (int i = 1; i <= m; i++)
		flag[i] = false;
 
	queue <int> q({s});
	vis[s] = true;
	while (q.size()) {
		int u = q.front();
		q.pop();
		for (int id : adj[u]) {
			int v = edge[id].se;
			if (!vis[v] && dis[s][u] + cost[id] == dis[s][v]) {
				vis[v] = true;
				q.push(v);
				newadj[u].push_back(id);
			}
		}
	}
 
	if (!vis[t]) {
		for (int i = 1; i <= m; i++) 
			f[i] = oo;
		return;	
	}
 
	d[s] = 0;
	dfs(s, -1);
 
	for (int u = t; u != s; u = edge[par[u]].fi) {
		flag[par[u]] = true;
		mark[u] = true;
	}
	mark[s] = true;
 
	for (int i = 1; i <= m; i++)
		f[i] = (flag[i]) ? oo : dis[s][t];
 
	for (int i = 1; i <= m; i++) if (!flag[i]) {
		int u = edge[i].fi;
		int v = edge[i].se;
		if (dis[s][u] == oo)
			continue;
		int res = dis[s][u] + dis[v][t] + cost[i]; 
		while (!mark[u]) 
			u = edge[par[u]].fi;
 
		if (d[v] < d[u]) 
			continue;
 
		if (mark[v]) {
			for (; v != u; v = edge[par[v]].fi)
				mini(f[par[v]], res);
		}
	}
}
 
signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> m;
	for (int i = 1; i <= m; i++)
		cin >> edge[i].fi >> edge[i].se >> cost[i] >> revcost[i];
	
	for (int i = 1; i <= n; i++)
	for (int j = 1; j <= n; j++)
		if (i != j)
			dis[i][j] = oo;
 
	for (int i = 1; i <= m; i++)  {
		int u = edge[i].fi;
		int v = edge[i].se;
		mini(dis[u][v], cost[i]); 
		adj[u].push_back(i);
	}
 
	for (int j = 1; j <= n; j++)
	for (int i = 1; i <= n; i++)
	for (int k = 1; k <= n; k++) 
		mini(dis[i][k], dis[i][j] + dis[j][k]);
 
	// for (int i = 1; i <= n; i++)
	// for (int j = 1; j <= n; j++)
	// 	cerr << i << " " << j << " " << dis[i][j] << "\n"
 
	int ans = 2 * oo;
	if (dis[1][n] < oo && dis[n][1] < oo)
		ans = min(ans, dis[1][n] + dis[n][1]);
 
	solve(f, 1, n);
	solve(g, n, 1);
 
	// for (int i = 1; i <= m; i++)
	// 	cerr << f[i] << " \n"[i == m];
 
	// for (int i = 1; i <= m; i++) 
	// 	cerr << g[i] << " \n"[i == m];
 
	for (int i = 1; i <= m; i++) {
		int u = edge[i].fi;
		int v = edge[i].se;
		int l = f[i];
		int r = g[i];
		if (dis[1][n] > dis[1][v] + dis[u][n] + cost[i]) 
			l = dis[1][v] + dis[u][n] + cost[i];
 
		if (dis[n][1] > dis[n][v] + dis[u][1] + cost[i])
			r = dis[n][v] + dis[u][1] + cost[i];
 
		// cerr << i << " " << l << " " << r << "\n";
 
		if (l < oo && r < oo)
			ans = min(ans, l + r + revcost[i]);
	}
 
	if (ans > 1e17)
		ans = -1;
	cout << ans;
	return 0;	
}

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 716 KB Output is correct
2 Correct 14 ms 692 KB Output is correct
3 Correct 20 ms 744 KB Output is correct
4 Correct 16 ms 748 KB Output is correct
5 Correct 2 ms 460 KB Output is correct
6 Correct 14 ms 684 KB Output is correct
7 Correct 1 ms 336 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 23 ms 748 KB Output is correct
11 Correct 18 ms 740 KB Output is correct
12 Correct 17 ms 740 KB Output is correct
13 Correct 15 ms 748 KB Output is correct
14 Correct 15 ms 716 KB Output is correct
15 Incorrect 15 ms 716 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 56 ms 3776 KB Output is correct
2 Correct 42 ms 3652 KB Output is correct
3 Correct 44 ms 3624 KB Output is correct
4 Correct 16 ms 764 KB Output is correct
5 Correct 22 ms 736 KB Output is correct
6 Correct 25 ms 696 KB Output is correct
7 Correct 14 ms 692 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 39 ms 4672 KB Output is correct
10 Correct 52 ms 4708 KB Output is correct
11 Correct 40 ms 4684 KB Output is correct
12 Correct 50 ms 4636 KB Output is correct
13 Correct 40 ms 4704 KB Output is correct
14 Correct 40 ms 4764 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 716 KB Output is correct
2 Correct 14 ms 588 KB Output is correct
3 Correct 32 ms 3716 KB Output is correct
4 Correct 14 ms 588 KB Output is correct
5 Correct 37 ms 4568 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 60 ms 4524 KB Output is correct
9 Correct 36 ms 4548 KB Output is correct
10 Correct 35 ms 4564 KB Output is correct
11 Correct 36 ms 4548 KB Output is correct
12 Correct 45 ms 4516 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 1 ms 332 KB Output is correct
17 Correct 1 ms 332 KB Output is correct
18 Correct 1 ms 332 KB Output is correct
19 Correct 41 ms 4604 KB Output is correct
20 Correct 37 ms 4600 KB Output is correct
21 Correct 36 ms 4532 KB Output is correct
22 Correct 38 ms 4564 KB Output is correct

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 716 KB Output is correct
2 Correct 14 ms 692 KB Output is correct
3 Correct 20 ms 744 KB Output is correct
4 Correct 16 ms 748 KB Output is correct
5 Correct 2 ms 460 KB Output is correct
6 Correct 14 ms 684 KB Output is correct
7 Correct 1 ms 336 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 23 ms 748 KB Output is correct
11 Correct 18 ms 740 KB Output is correct
12 Correct 17 ms 740 KB Output is correct
13 Correct 15 ms 748 KB Output is correct
14 Correct 15 ms 716 KB Output is correct
15 Incorrect 15 ms 716 KB Output isn't correct
16 Halted 0 ms 0 KB -