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Submission #417333

# Submission time Handle Problem Language Result Execution time Memory
417333 2021-06-03T14:54:37 Z AmineWeslati Olympic Bus (JOI20_ho_t4) C++14
100 / 100
 997 ms 3952 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<int>vi; 
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x),end(x)

typedef pair<int,int>pi;
#define fi first
#define se second

#define FOR(i,a,b) for(int i=a; i<b; i++)
#define ROF(i,a,b) for(int i=b-1; i>=a; i--)

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
#endif
}
//--------------------------------

void ckmin(int &x, int y){x=min(x,y);}

const int INF=1e9+100;
const int MX=5e4+10;

int N,M,U[MX],V[MX],W[MX],C[MX];

vector<pair<pi,int>>adj[MX];
void build(int m){
	FOR(i,1,N+1) adj[i].clear();
	FOR(i,0,M){
		int u=U[i],v=V[i],w=W[i];
		if(m) swap(u,v);
		adj[u].pb({{v,w},i});
	}
}

int dist[MX],par[MX],par_idx[MX];
int fu=-1,fv=-1,fidx=-1; 
void dijkstra(int s){
	FOR(i,1,N+1) dist[i]=INF;
	dist[s]=0;

	priority_queue<pi,vector<pi>,greater<pi>>q;
	q.push({0,s});

	while(sz(q)){
		int u=q.top().se,d=q.top().fi;
		q.pop();

		if(d>dist[u]) continue;

		for(auto it: adj[u]){
			int v=it.fi.fi,w=it.fi.se,idx=it.se; 
			if(!(fu==u && fv==v && fidx==idx) && dist[v]>d+w){
				dist[v]=d+w; 
				par[v]=u; 
				par_idx[v]=idx;
				q.push({dist[v],v});
			}
		}
	}
}

vi chosen(MX,0);
int to1[MX],toN[MX],from1[MX],fromN[MX];
void precompute(){
	build(0);

	dijkstra(1);
	FOR(i,1,N+1) from1[i]=dist[i];

	int u=N; 
	while(dist[N]!=INF && u!=1){
		chosen[par_idx[u]]=1;
		u=par[u];
	}

	dijkstra(N);
	FOR(i,1,N+1) fromN[i]=dist[i];

	u=1;
	while(dist[1]!=INF && u!=N){
		chosen[par_idx[u]]=1;
		u=par[u];
	}
	

	build(1);

	dijkstra(1);
	FOR(i,1,N+1) to1[i]=dist[i];

	dijkstra(N);
	FOR(i,1,N+1) toN[i]=dist[i];
}

int main(){
	IO();

	cin>>N>>M;
	FOR(i,0,M) cin>>U[i]>>V[i]>>W[i]>>C[i];

	precompute();

	int ans=2e9;
	if(toN[1]!=INF && to1[N]!=INF) ans=toN[1]+to1[N]; 

	build(0);
	FOR(i,0,M){
		if(chosen[i]){
			adj[V[i]].pb({{U[i],W[i]},i});
			fu=U[i],fv=V[i],fidx=i;

			int x=C[i];
			dijkstra(1);
			if(dist[N]!=INF){
				x+=dist[N];
				dijkstra(N);
				if(dist[1]!=INF){
					x+=dist[1];
					ckmin(ans,x);
				}
			}
			
			adj[V[i]].pop_back();
			fu=-1; fv=-1;
		}
		else{
			int u=U[i],v=V[i];
			swap(u,v);

			bool c1=(max(max(from1[u],toN[v]),fromN[1])!=INF),
			c2=(max(max(from1[N],to1[v]),fromN[u])!=INF),
			c3=(max(max(from1[u],toN[v]),max(fromN[u],to1[v]))!=INF);

			if(c1)
			ckmin(ans,from1[u]+W[i]+C[i]+toN[v]+fromN[1]);
			if(c2)
			ckmin(ans,from1[N]+fromN[u]+C[i]+W[i]+to1[v]);
			if(c3)
			ckmin(ans,from1[u]+W[i]+C[i]+toN[v]+fromN[u]+W[i]+to1[v]);
		}
	}

	if(ans>=2e9) ans=-1;
	cout << ans << endl;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 1740 KB Output is correct
2 Correct 2 ms 1740 KB Output is correct
3 Correct 3 ms 1740 KB Output is correct
4 Correct 3 ms 1740 KB Output is correct
5 Correct 3 ms 1740 KB Output is correct
6 Correct 2 ms 1740 KB Output is correct
7 Correct 1 ms 1612 KB Output is correct
8 Correct 1 ms 1612 KB Output is correct
9 Correct 3 ms 1716 KB Output is correct
10 Correct 19 ms 1740 KB Output is correct
11 Correct 25 ms 1740 KB Output is correct
12 Correct 24 ms 1740 KB Output is correct
13 Correct 3 ms 1740 KB Output is correct
14 Correct 3 ms 1740 KB Output is correct
15 Correct 3 ms 1740 KB Output is correct
16 Correct 3 ms 1740 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 66 ms 3728 KB Output is correct
2 Correct 64 ms 3652 KB Output is correct
3 Correct 71 ms 3656 KB Output is correct
4 Correct 4 ms 1740 KB Output is correct
5 Correct 4 ms 1740 KB Output is correct
6 Correct 2 ms 1740 KB Output is correct
7 Correct 2 ms 1740 KB Output is correct
8 Correct 1 ms 1612 KB Output is correct
9 Correct 67 ms 3836 KB Output is correct
10 Correct 72 ms 3772 KB Output is correct
11 Correct 69 ms 3596 KB Output is correct
12 Correct 70 ms 3768 KB Output is correct
13 Correct 68 ms 3572 KB Output is correct
14 Correct 69 ms 3540 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1740 KB Output is correct
2 Correct 2 ms 1740 KB Output is correct
3 Correct 48 ms 2992 KB Output is correct
4 Correct 2 ms 1740 KB Output is correct
5 Correct 62 ms 3576 KB Output is correct
6 Correct 1 ms 1612 KB Output is correct
7 Correct 1 ms 1612 KB Output is correct
8 Correct 60 ms 3816 KB Output is correct
9 Correct 67 ms 3788 KB Output is correct
10 Correct 60 ms 3524 KB Output is correct
11 Correct 61 ms 3524 KB Output is correct
12 Correct 67 ms 3560 KB Output is correct
13 Correct 1 ms 1612 KB Output is correct
14 Correct 1 ms 1612 KB Output is correct
15 Correct 1 ms 1612 KB Output is correct
16 Correct 2 ms 1612 KB Output is correct
17 Correct 1 ms 1688 KB Output is correct
18 Correct 2 ms 1612 KB Output is correct
19 Correct 60 ms 3480 KB Output is correct
20 Correct 60 ms 3520 KB Output is correct
21 Correct 64 ms 3480 KB Output is correct
22 Correct 60 ms 3600 KB Output is correct

Subtask #4
63.0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 1740 KB Output is correct
2 Correct 2 ms 1740 KB Output is correct
3 Correct 3 ms 1740 KB Output is correct
4 Correct 3 ms 1740 KB Output is correct
5 Correct 3 ms 1740 KB Output is correct
6 Correct 2 ms 1740 KB Output is correct
7 Correct 1 ms 1612 KB Output is correct
8 Correct 1 ms 1612 KB Output is correct
9 Correct 3 ms 1716 KB Output is correct
10 Correct 19 ms 1740 KB Output is correct
11 Correct 25 ms 1740 KB Output is correct
12 Correct 24 ms 1740 KB Output is correct
13 Correct 3 ms 1740 KB Output is correct
14 Correct 3 ms 1740 KB Output is correct
15 Correct 3 ms 1740 KB Output is correct
16 Correct 3 ms 1740 KB Output is correct
17 Correct 66 ms 3728 KB Output is correct
18 Correct 64 ms 3652 KB Output is correct
19 Correct 71 ms 3656 KB Output is correct
20 Correct 4 ms 1740 KB Output is correct
21 Correct 4 ms 1740 KB Output is correct
22 Correct 2 ms 1740 KB Output is correct
23 Correct 2 ms 1740 KB Output is correct
24 Correct 1 ms 1612 KB Output is correct
25 Correct 67 ms 3836 KB Output is correct
26 Correct 72 ms 3772 KB Output is correct
27 Correct 69 ms 3596 KB Output is correct
28 Correct 70 ms 3768 KB Output is correct
29 Correct 68 ms 3572 KB Output is correct
30 Correct 69 ms 3540 KB Output is correct
31 Correct 3 ms 1740 KB Output is correct
32 Correct 2 ms 1740 KB Output is correct
33 Correct 48 ms 2992 KB Output is correct
34 Correct 2 ms 1740 KB Output is correct
35 Correct 62 ms 3576 KB Output is correct
36 Correct 1 ms 1612 KB Output is correct
37 Correct 1 ms 1612 KB Output is correct
38 Correct 60 ms 3816 KB Output is correct
39 Correct 67 ms 3788 KB Output is correct
40 Correct 60 ms 3524 KB Output is correct
41 Correct 61 ms 3524 KB Output is correct
42 Correct 67 ms 3560 KB Output is correct
43 Correct 1 ms 1612 KB Output is correct
44 Correct 1 ms 1612 KB Output is correct
45 Correct 1 ms 1612 KB Output is correct
46 Correct 2 ms 1612 KB Output is correct
47 Correct 1 ms 1688 KB Output is correct
48 Correct 2 ms 1612 KB Output is correct
49 Correct 60 ms 3480 KB Output is correct
50 Correct 60 ms 3520 KB Output is correct
51 Correct 64 ms 3480 KB Output is correct
52 Correct 60 ms 3600 KB Output is correct
53 Correct 68 ms 3580 KB Output is correct
54 Correct 66 ms 3524 KB Output is correct
55 Correct 67 ms 3540 KB Output is correct
56 Correct 4 ms 1740 KB Output is correct
57 Correct 3 ms 1740 KB Output is correct
58 Correct 114 ms 2984 KB Output is correct
59 Correct 130 ms 3064 KB Output is correct
60 Correct 167 ms 3148 KB Output is correct
61 Correct 112 ms 3032 KB Output is correct
62 Correct 127 ms 3012 KB Output is correct
63 Correct 177 ms 3048 KB Output is correct
64 Correct 724 ms 3692 KB Output is correct
65 Correct 775 ms 3792 KB Output is correct
66 Correct 997 ms 3792 KB Output is correct
67 Correct 51 ms 3952 KB Output is correct
68 Correct 72 ms 3788 KB Output is correct
69 Correct 67 ms 3736 KB Output is correct
70 Correct 70 ms 3528 KB Output is correct
71 Correct 70 ms 3480 KB Output is correct
72 Correct 70 ms 3596 KB Output is correct
73 Correct 73 ms 3552 KB Output is correct
74 Correct 73 ms 3596 KB Output is correct