oj.uz

Submission #224111

# Submission time Handle Problem Language Result Execution time Memory
224111 2020-04-17T08:10:21 Z errorgorn Olympic Bus (JOI20_ho_t4) C++14
16 / 100
 82 ms 8560 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl;

#define rep(x,start,end) for(auto x=start-(start>end);x!=end-(start>end);x+=(start<end?1:-1))
#define all(x) x.begin(),x.end()

ll MAX(ll a){return a;}
ll MIN(ll a){return a;}
template<typename... Args>
ll MAX(ll a, Args... args) { return max(a,MAX(args...)); }
template<typename... Args>
ll MIN(ll a, Args... args) { return min(a,MIN(args...)); }

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>

const ll INF=1e18;

struct E{
	int u,v;
	ll len,flip;
	int id;

	E(int a,int b,int c,int d,int e){
		u=a,v=b;
		len=c,flip=d;
		id=e;
	}
};

int n,m;
vector<E> al[205];
vector<E> al_rev[205]; //store reversed edges
vector<E> edges;

priority_queue<ii,vector<ii>,greater<ii> > pq;
ll sf[205]; //source front
ll sb[205]; //source back
ll tf[205]; //sink front
ll tb[205]; //sink back

ll w1[205];
ll w2[205];

bool path[50005]; //is some edge in SP

ll temp,node; //stuff for dijk

void initial_d(){ //epic name
	rep(x,0,205) sf[x]=sb[x]=tf[x]=tb[x]=INF;
	
	sf[1]=0;
	pq.push(ii(sf[1],1));
	while (!pq.empty()){
		temp=pq.top().first;
		node=pq.top().second;
		pq.pop();
		if (temp>sf[node]) continue; //important
		for (auto &it:al[node]){
			if (sf[it.v]>sf[node]+it.len){
				sf[it.v]=sf[node]+it.len;
				pq.push(ii (sf[it.v],it.v));
			}
		}
	} 
	
	sb[1]=0;
	pq.push(ii(sb[1],1));
	while (!pq.empty()){
		temp=pq.top().first;
		node=pq.top().second;
		pq.pop();
		if (temp>sb[node]) continue; //important
		for (auto &it:al_rev[node]){
			if (sb[it.v]>sb[node]+it.len){
				sb[it.v]=sb[node]+it.len;
				pq.push(ii (sb[it.v],it.v));
			}
		}
	} 
	
	tf[n]=0;
	pq.push(ii(tf[n],n));
	while (!pq.empty()){
		temp=pq.top().first;
		node=pq.top().second;
		pq.pop();
		if (temp>tf[node]) continue; //important
		for (auto &it:al[node]){
			if (tf[it.v]>tf[node]+it.len){
				tf[it.v]=tf[node]+it.len;
				pq.push(ii (tf[it.v],it.v));
			}
		}
	} 
	
	tb[n]=0;
	pq.push(ii(tb[n],n));
	while (!pq.empty()){
		temp=pq.top().first;
		node=pq.top().second;
		pq.pop();
		if (temp>tb[node]) continue; //important
		for (auto &it:al_rev[node]){
			if (tb[it.v]>tb[node]+it.len){
				tb[it.v]=tb[node]+it.len;
				pq.push(ii (tb[it.v],it.v));
			}
		}
	}
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin>>n>>m;
	
	int a,b,c,d;
	rep(x,0,m){
		cin>>a>>b>>c>>d;
		
		al[a].push_back(E(a,b,c,d,x));
		al_rev[b].push_back(E(b,a,c,d,x));
		edges.push_back(E(a,b,c,d,x));
	}
	
	initial_d();
	
	//try dijk start and end
	ll ans=sf[n]+tf[1];
	
	if (m>1000){
		for (auto &it:edges){
			ans=min(ans,min(sf[n],sf[it.v]+it.len+tb[it.u])+min(tf[1],tf[it.v]+it.len+sb[it.u])+it.flip);
		}
		
		cout<<ans<<endl;
		return 0;
	}
	
	/*
	rep(x,1,n+1){
		cout<<sf[x]<<" "<<sb[x]<<" "<<tf[x]<<" "<<tb[x]<<endl;
	}
	*/
	
	rep(bad,0,m){
		//we run a new iteration of dijkstra for this where we flip every edge on the SP
		//cout<<edges[bad].u<<" "<<edges[bad].v<<endl;
		
		al[edges[bad].v].push_back(E(-1,edges[bad].u,edges[bad].len,-1,-1));
		
		rep(x,0,205) w1[x]=w2[x]=INF;
		
		w1[1]=0;
		pq.push(ii(w1[1],1));
		while (!pq.empty()){
			temp=pq.top().first;
			node=pq.top().second;
			pq.pop();
			if (temp>w1[node]) continue; //important
			for (auto &it:al[node]){
				if (it.id==edges[bad].id) continue;
				if (w1[it.v]>w1[node]+it.len){
					w1[it.v]=w1[node]+it.len;
					pq.push(ii (w1[it.v],it.v));
				}
			}
		}
		
		w2[n]=0;
		pq.push(ii(w2[n],n));
		while (!pq.empty()){
			temp=pq.top().first;
			node=pq.top().second;
			pq.pop();
			if (temp>w2[node]) continue; //important
			for (auto &it:al[node]){
				if (it.id==edges[bad].id) continue;
				if (w2[it.v]>w2[node]+it.len){
					w2[it.v]=w2[node]+it.len;
					pq.push(ii (w2[it.v],it.v));
				}
			}
		}
		
		ans=min(ans,w1[n]+w2[1]+edges[bad].flip);
		al[edges[bad].v].pop_back();
	}
	
	if (ans>=INF) cout<<-1<<endl;
	else cout<<ans<<endl;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 52 ms 512 KB Output is correct
4 Correct 56 ms 512 KB Output is correct
5 Correct 17 ms 512 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 9 ms 512 KB Output is correct
10 Correct 82 ms 512 KB Output is correct
11 Correct 78 ms 512 KB Output is correct
12 Correct 79 ms 632 KB Output is correct
13 Correct 28 ms 512 KB Output is correct
14 Correct 35 ms 432 KB Output is correct
15 Correct 32 ms 512 KB Output is correct
16 Correct 37 ms 512 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 6896 KB Output is correct
2 Correct 31 ms 6896 KB Output is correct
3 Correct 33 ms 6768 KB Output is correct
4 Correct 6 ms 640 KB Output is correct
5 Correct 31 ms 512 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 6 ms 512 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 32 ms 6756 KB Output is correct
10 Correct 32 ms 8040 KB Output is correct
11 Correct 32 ms 7792 KB Output is correct
12 Correct 32 ms 7920 KB Output is correct
13 Correct 33 ms 7784 KB Output is correct
14 Correct 33 ms 8560 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 632 KB Output is correct
2 Correct 6 ms 384 KB Output is correct
3 Correct 25 ms 6004 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 29 ms 6504 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 28 ms 6376 KB Output is correct
9 Correct 30 ms 7784 KB Output is correct
10 Incorrect 29 ms 7504 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 52 ms 512 KB Output is correct
4 Correct 56 ms 512 KB Output is correct
5 Correct 17 ms 512 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 9 ms 512 KB Output is correct
10 Correct 82 ms 512 KB Output is correct
11 Correct 78 ms 512 KB Output is correct
12 Correct 79 ms 632 KB Output is correct
13 Correct 28 ms 512 KB Output is correct
14 Correct 35 ms 432 KB Output is correct
15 Correct 32 ms 512 KB Output is correct
16 Correct 37 ms 512 KB Output is correct
17 Correct 33 ms 6896 KB Output is correct
18 Correct 31 ms 6896 KB Output is correct
19 Correct 33 ms 6768 KB Output is correct
20 Correct 6 ms 640 KB Output is correct
21 Correct 31 ms 512 KB Output is correct
22 Correct 5 ms 384 KB Output is correct
23 Correct 6 ms 512 KB Output is correct
24 Correct 4 ms 384 KB Output is correct
25 Correct 32 ms 6756 KB Output is correct
26 Correct 32 ms 8040 KB Output is correct
27 Correct 32 ms 7792 KB Output is correct
28 Correct 32 ms 7920 KB Output is correct
29 Correct 33 ms 7784 KB Output is correct
30 Correct 33 ms 8560 KB Output is correct
31 Correct 36 ms 632 KB Output is correct
32 Correct 6 ms 384 KB Output is correct
33 Correct 25 ms 6004 KB Output is correct
34 Correct 5 ms 384 KB Output is correct
35 Correct 29 ms 6504 KB Output is correct
36 Correct 5 ms 384 KB Output is correct
37 Correct 4 ms 384 KB Output is correct
38 Correct 28 ms 6376 KB Output is correct
39 Correct 30 ms 7784 KB Output is correct
40 Incorrect 29 ms 7504 KB Output isn't correct
41 Halted 0 ms 0 KB -