oj.uz

Submission #861087

# Submission time Handle Problem Language Result Execution time Memory
861087 2023-10-15T09:19:49 Z phoenix0423 Olympic Bus (JOI20_ho_t4) C++17
100 / 100
 237 ms 22092 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[50004], crit[50004];

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);
	vector<int> from(n), from2(n);
	dist[0] = 0, dist2[n - 1] = 0, rdist[n - 1] = 0, rdist2[0] = 0;
	auto dijkstra = [&](vector<ll>& dist, vector<int>& from) -> 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];
				if(dist[b] > dist[a] + c) from[b] = a;
				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, from);
	dijkstra(dist2, from2);
	rdijkstra(rdist);
	rdijkstra(rdist2);
	auto find_crit = [&](int st, int ed, vector<ll> &dist, vector<int> &from){
		if(dist[ed] >= INF) return;
		int pos = ed;
		while(pos != st){
			int org = pos;
			for(auto x : radj[pos]){
				auto [a, b, c, d] = e[x];
				if(dist[pos] == dist[a] + c && from[pos] == a){
					crit[x] = 1;
					pos = a;
					break;
				}
			}
		}
	};
	find_crit(0, n - 1, dist, from);
	find_crit(n - 1, 0, dist2, from2);
	ll ans = dist[n - 1] + dist2[0];
	int cnt = 0;
	for(int i = 0; i < m; i++){
		auto [a, b, c, d] = e[i];
		if(crit[i]){
			cnt++;
			if(cnt > n * 2) break;
			// if(cnt > n * 10) break;
			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, from), dijkstra(ndist2, from);
			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";
}

Compilation message

ho_t4.cpp: In lambda function:
ho_t4.cpp:74:8: warning: unused variable 'org' [-Wunused-variable]
   74 |    int org = pos;
      |        ^~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 19288 KB Output is correct
2 Correct 5 ms 19292 KB Output is correct
3 Correct 6 ms 19508 KB Output is correct
4 Correct 7 ms 19288 KB Output is correct
5 Correct 4 ms 19292 KB Output is correct
6 Correct 4 ms 19292 KB Output is correct
7 Correct 4 ms 19292 KB Output is correct
8 Correct 4 ms 19292 KB Output is correct
9 Correct 4 ms 19288 KB Output is correct
10 Correct 41 ms 19504 KB Output is correct
11 Correct 54 ms 19292 KB Output is correct
12 Correct 50 ms 19496 KB Output is correct
13 Correct 5 ms 19288 KB Output is correct
14 Correct 6 ms 19292 KB Output is correct
15 Correct 6 ms 19432 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 21 ms 20944 KB Output is correct
2 Correct 22 ms 20796 KB Output is correct
3 Correct 24 ms 20948 KB Output is correct
4 Correct 6 ms 19544 KB Output is correct
5 Correct 8 ms 19292 KB Output is correct
6 Correct 5 ms 19292 KB Output is correct
7 Correct 4 ms 19488 KB Output is correct
8 Correct 4 ms 19292 KB Output is correct
9 Correct 19 ms 20804 KB Output is correct
10 Correct 18 ms 20812 KB Output is correct
11 Correct 23 ms 20820 KB Output is correct
12 Correct 22 ms 20944 KB Output is correct
13 Correct 22 ms 20824 KB Output is correct
14 Correct 22 ms 20944 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 19292 KB Output is correct
2 Correct 5 ms 19292 KB Output is correct
3 Correct 17 ms 20792 KB Output is correct
4 Correct 4 ms 19292 KB Output is correct
5 Correct 18 ms 20948 KB Output is correct
6 Correct 4 ms 19292 KB Output is correct
7 Correct 5 ms 19292 KB Output is correct
8 Correct 17 ms 20808 KB Output is correct
9 Correct 16 ms 20880 KB Output is correct
10 Correct 20 ms 20884 KB Output is correct
11 Correct 19 ms 20948 KB Output is correct
12 Correct 19 ms 20948 KB Output is correct
13 Correct 4 ms 19292 KB Output is correct
14 Correct 5 ms 19288 KB Output is correct
15 Correct 4 ms 19544 KB Output is correct
16 Correct 4 ms 19292 KB Output is correct
17 Correct 4 ms 19292 KB Output is correct
18 Correct 4 ms 19292 KB Output is correct
19 Correct 18 ms 20772 KB Output is correct
20 Correct 19 ms 21716 KB Output is correct
21 Correct 28 ms 21740 KB Output is correct
22 Correct 19 ms 21716 KB Output is correct

Subtask #4
63.0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 19288 KB Output is correct
2 Correct 5 ms 19292 KB Output is correct
3 Correct 6 ms 19508 KB Output is correct
4 Correct 7 ms 19288 KB Output is correct
5 Correct 4 ms 19292 KB Output is correct
6 Correct 4 ms 19292 KB Output is correct
7 Correct 4 ms 19292 KB Output is correct
8 Correct 4 ms 19292 KB Output is correct
9 Correct 4 ms 19288 KB Output is correct
10 Correct 41 ms 19504 KB Output is correct
11 Correct 54 ms 19292 KB Output is correct
12 Correct 50 ms 19496 KB Output is correct
13 Correct 5 ms 19288 KB Output is correct
14 Correct 6 ms 19292 KB Output is correct
15 Correct 6 ms 19432 KB Output is correct
16 Correct 6 ms 19292 KB Output is correct
17 Correct 21 ms 20944 KB Output is correct
18 Correct 22 ms 20796 KB Output is correct
19 Correct 24 ms 20948 KB Output is correct
20 Correct 6 ms 19544 KB Output is correct
21 Correct 8 ms 19292 KB Output is correct
22 Correct 5 ms 19292 KB Output is correct
23 Correct 4 ms 19488 KB Output is correct
24 Correct 4 ms 19292 KB Output is correct
25 Correct 19 ms 20804 KB Output is correct
26 Correct 18 ms 20812 KB Output is correct
27 Correct 23 ms 20820 KB Output is correct
28 Correct 22 ms 20944 KB Output is correct
29 Correct 22 ms 20824 KB Output is correct
30 Correct 22 ms 20944 KB Output is correct
31 Correct 6 ms 19292 KB Output is correct
32 Correct 5 ms 19292 KB Output is correct
33 Correct 17 ms 20792 KB Output is correct
34 Correct 4 ms 19292 KB Output is correct
35 Correct 18 ms 20948 KB Output is correct
36 Correct 4 ms 19292 KB Output is correct
37 Correct 5 ms 19292 KB Output is correct
38 Correct 17 ms 20808 KB Output is correct
39 Correct 16 ms 20880 KB Output is correct
40 Correct 20 ms 20884 KB Output is correct
41 Correct 19 ms 20948 KB Output is correct
42 Correct 19 ms 20948 KB Output is correct
43 Correct 4 ms 19292 KB Output is correct
44 Correct 5 ms 19288 KB Output is correct
45 Correct 4 ms 19544 KB Output is correct
46 Correct 4 ms 19292 KB Output is correct
47 Correct 4 ms 19292 KB Output is correct
48 Correct 4 ms 19292 KB Output is correct
49 Correct 18 ms 20772 KB Output is correct
50 Correct 19 ms 21716 KB Output is correct
51 Correct 28 ms 21740 KB Output is correct
52 Correct 19 ms 21716 KB Output is correct
53 Correct 28 ms 21908 KB Output is correct
54 Correct 35 ms 21716 KB Output is correct
55 Correct 35 ms 21716 KB Output is correct
56 Correct 8 ms 19292 KB Output is correct
57 Correct 7 ms 19428 KB Output is correct
58 Correct 142 ms 21716 KB Output is correct
59 Correct 140 ms 21632 KB Output is correct
60 Correct 178 ms 21652 KB Output is correct
61 Correct 114 ms 21712 KB Output is correct
62 Correct 135 ms 21736 KB Output is correct
63 Correct 181 ms 21716 KB Output is correct
64 Correct 160 ms 21640 KB Output is correct
65 Correct 180 ms 21588 KB Output is correct
66 Correct 237 ms 21584 KB Output is correct
67 Correct 15 ms 21716 KB Output is correct
68 Correct 18 ms 21908 KB Output is correct
69 Correct 22 ms 22092 KB Output is correct
70 Correct 27 ms 21996 KB Output is correct
71 Correct 23 ms 21972 KB Output is correct
72 Correct 23 ms 21972 KB Output is correct
73 Correct 28 ms 21968 KB Output is correct
74 Correct 28 ms 21956 KB Output is correct