oj.uz

Submission #861073

# Submission time Handle Problem Language Result Execution time Memory
861073 2023-10-15T08:54:55 Z phoenix0423 Olympic Bus (JOI20_ho_t4) C++17
16 / 100
 1000 ms 21956 KB 
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#pragma GCC optimize("Ofast")
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define lowbit(x) x&-x
#define ckmin(a, b) a = min(a, b)
#define ckmax(a, b) a = max(a, b)
const int maxn = 4e5 + 5;
const ll INF = 2e9 + 7;
struct edge{
	int a, b, c, d;
	edge(){}
	edge(int _a, int _b, int _c, int _d) : a(_a), b(_b), c(_c), d(_d){}
};
int n, m;
vector<int> adj[maxn], radj[maxn];
vector<edge> e;
int invalid[50000 + 4];

int main(void){
	fastio;
	cin>>n>>m;
	for(int i = 0; i < m; i++){
		int a, b, c, d;
		cin>>a>>b>>c>>d;
		a--, b--;
		adj[a].pb(i);
		radj[b].pb(i);
		e.pb(edge(a, b, c, d));
	}
	vector<ll> dist(n, INF), dist2(n, INF), rdist(n, INF), rdist2(n, INF);
	dist[0] = 0, dist2[n - 1] = 0, rdist[n - 1] = 0, rdist2[0] = 0;
	auto dijkstra = [&](vector<ll>& dist) -> void{
		vector<int> vis(n);
		for(int i = 0; i < n; i++){
			ll mn = INF, id = 0;
			for(int j = 0; j < n; j++) if(!vis[j] && dist[j] < mn) mn = dist[j], id = j;
			vis[id] = 1;
			for(auto x : adj[id]){
				if(invalid[x]) continue;
				auto [a, b, c, d] = e[x];
				dist[b] = min(dist[b], dist[a] + c);
			}
		}
	};
	auto rdijkstra = [&](vector<ll>& dist) -> void{
		vector<int> vis(n);
		for(int i = 0; i < n; i++){
			ll mn = INF, id = 0;
			for(int j = 0; j < n; j++) if(!vis[j] && dist[j] < mn) mn = dist[j], id = j;
			vis[id] = 1;
			for(auto x : radj[id]){
				auto [a, b, c, d] = e[x];
				dist[a] = min(dist[a], dist[b] + c);
			}
		}
	};
	dijkstra(dist);
	dijkstra(dist2);
	rdijkstra(rdist);
	rdijkstra(rdist2);
	ll ans = dist[n - 1] + dist2[0];
	for(int i = 0; i < m; i++){
		auto [a, b, c, d] = e[i];
		if((dist[a] + rdist[b] + c == dist[n - 1] && dist[n - 1] < INF) || (dist2[a] + rdist2[b] + c == dist2[0] && dist2[0] < INF)){
			invalid[i] = 1;
			e.pb(edge(b, a, c, d));
			adj[b].pb(m);
			vector<ll> ndist(n, INF), ndist2(n, INF);
			ndist[0] = 0, ndist2[n - 1] = 0;
			dijkstra(ndist), dijkstra(ndist2);
			ans = min(ans, ndist[n - 1] + ndist2[0] + d);
			e.pop_back();
			adj[b].pop_back();
			invalid[i] = 0;
			continue;
		}
		//invert : becomes b->a
		ll d1 = min(dist[n - 1], dist[b] + rdist[a] + c);
		ll d2 = min(dist2[0], dist2[b] + rdist2[a] + c);
		ans = min(ans, d1 + d2 + d);
	}
	cout<<(ans < INF ? ans : -1)<<"\n";
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 104 ms 19292 KB Output is correct
2 Correct 4 ms 19036 KB Output is correct
3 Correct 6 ms 19292 KB Output is correct
4 Correct 7 ms 19292 KB Output is correct
5 Correct 5 ms 19292 KB Output is correct
6 Correct 4 ms 19292 KB Output is correct
7 Correct 4 ms 19036 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 5 ms 19292 KB Output is correct
10 Correct 40 ms 19316 KB Output is correct
11 Correct 52 ms 19292 KB Output is correct
12 Correct 55 ms 19292 KB Output is correct
13 Correct 4 ms 19292 KB Output is correct
14 Correct 6 ms 19328 KB Output is correct
15 Correct 7 ms 19292 KB Output is correct
16 Correct 6 ms 19292 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 20692 KB Output is correct
2 Correct 26 ms 20628 KB Output is correct
3 Correct 26 ms 20692 KB Output is correct
4 Correct 7 ms 19360 KB Output is correct
5 Correct 10 ms 19312 KB Output is correct
6 Correct 6 ms 19288 KB Output is correct
7 Correct 4 ms 19292 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 17 ms 20560 KB Output is correct
10 Correct 21 ms 20656 KB Output is correct
11 Correct 28 ms 20564 KB Output is correct
12 Correct 25 ms 20688 KB Output is correct
13 Correct 25 ms 21828 KB Output is correct
14 Correct 29 ms 21956 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 106 ms 19292 KB Output is correct
2 Correct 11 ms 19288 KB Output is correct
3 Execution timed out 1044 ms 20692 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 104 ms 19292 KB Output is correct
2 Correct 4 ms 19036 KB Output is correct
3 Correct 6 ms 19292 KB Output is correct
4 Correct 7 ms 19292 KB Output is correct
5 Correct 5 ms 19292 KB Output is correct
6 Correct 4 ms 19292 KB Output is correct
7 Correct 4 ms 19036 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 5 ms 19292 KB Output is correct
10 Correct 40 ms 19316 KB Output is correct
11 Correct 52 ms 19292 KB Output is correct
12 Correct 55 ms 19292 KB Output is correct
13 Correct 4 ms 19292 KB Output is correct
14 Correct 6 ms 19328 KB Output is correct
15 Correct 7 ms 19292 KB Output is correct
16 Correct 6 ms 19292 KB Output is correct
17 Correct 26 ms 20692 KB Output is correct
18 Correct 26 ms 20628 KB Output is correct
19 Correct 26 ms 20692 KB Output is correct
20 Correct 7 ms 19360 KB Output is correct
21 Correct 10 ms 19312 KB Output is correct
22 Correct 6 ms 19288 KB Output is correct
23 Correct 4 ms 19292 KB Output is correct
24 Correct 4 ms 19036 KB Output is correct
25 Correct 17 ms 20560 KB Output is correct
26 Correct 21 ms 20656 KB Output is correct
27 Correct 28 ms 20564 KB Output is correct
28 Correct 25 ms 20688 KB Output is correct
29 Correct 25 ms 21828 KB Output is correct
30 Correct 29 ms 21956 KB Output is correct
31 Correct 106 ms 19292 KB Output is correct
32 Correct 11 ms 19288 KB Output is correct
33 Execution timed out 1044 ms 20692 KB Time limit exceeded
34 Halted 0 ms 0 KB -