oj.uz

Submission #861072

# Submission time Handle Problem Language Result Execution time Memory
861072 2023-10-15T08:50:19 Z phoenix0423 Olympic Bus (JOI20_ho_t4) C++17
5 / 100
 1000 ms 21844 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[10000];

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 108 ms 19288 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 19216 KB Output is correct
6 Correct 4 ms 19132 KB Output is correct
7 Correct 4 ms 19036 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 4 ms 19036 KB Output is correct
10 Correct 48 ms 19292 KB Output is correct
11 Correct 53 ms 19292 KB Output is correct
12 Correct 48 ms 19288 KB Output is correct
13 Correct 5 ms 19292 KB Output is correct
14 Correct 7 ms 19292 KB Output is correct
15 Correct 6 ms 19316 KB Output is correct
16 Correct 6 ms 19292 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 20688 KB Output is correct
2 Correct 27 ms 20688 KB Output is correct
3 Correct 27 ms 20692 KB Output is correct
4 Correct 7 ms 19292 KB Output is correct
5 Correct 10 ms 19292 KB Output is correct
6 Correct 4 ms 19032 KB Output is correct
7 Correct 4 ms 19036 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 22 ms 20560 KB Output is correct
10 Correct 18 ms 21832 KB Output is correct
11 Correct 30 ms 21844 KB Output is correct
12 Incorrect 23 ms 21744 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 105 ms 19292 KB Output is correct
2 Correct 12 ms 19032 KB Output is correct
3 Execution timed out 1065 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 108 ms 19288 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 19216 KB Output is correct
6 Correct 4 ms 19132 KB Output is correct
7 Correct 4 ms 19036 KB Output is correct
8 Correct 4 ms 19036 KB Output is correct
9 Correct 4 ms 19036 KB Output is correct
10 Correct 48 ms 19292 KB Output is correct
11 Correct 53 ms 19292 KB Output is correct
12 Correct 48 ms 19288 KB Output is correct
13 Correct 5 ms 19292 KB Output is correct
14 Correct 7 ms 19292 KB Output is correct
15 Correct 6 ms 19316 KB Output is correct
16 Correct 6 ms 19292 KB Output is correct
17 Correct 25 ms 20688 KB Output is correct
18 Correct 27 ms 20688 KB Output is correct
19 Correct 27 ms 20692 KB Output is correct
20 Correct 7 ms 19292 KB Output is correct
21 Correct 10 ms 19292 KB Output is correct
22 Correct 4 ms 19032 KB Output is correct
23 Correct 4 ms 19036 KB Output is correct
24 Correct 4 ms 19036 KB Output is correct
25 Correct 22 ms 20560 KB Output is correct
26 Correct 18 ms 21832 KB Output is correct
27 Correct 30 ms 21844 KB Output is correct
28 Incorrect 23 ms 21744 KB Output isn't correct
29 Halted 0 ms 0 KB -