oj.uz

답안 #224771

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
224771 2020-04-18T18:46:17 Z errorgorn Olympic Bus (JOI20_ho_t4) C++14
100 / 100
 661 ms 8040 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
int ps[205]; //parent front
ll sb[205]; //source back
int pt[205]; //parent back
ll tf[205]; //sink front
ll tb[205]; //sink back

ll w[205];

map<int,ll> sp_f,sp_b; //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;
				ps[it.v]=it.id;
				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;
				pt[it.v]=it.id;
				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));
			}
		}
	}
}

void SP_d(){
	if (sf[n]!=INF){ //find best from S to T
		int curr=n;
		
		while (curr!=1){
			//debug(ps[curr]);
			sp_f[ps[curr]]=INF;
			curr=edges[ps[curr]].u;
		}
		
		for (auto &it2:sp_f){
			//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;
			rep(x,0,205) w[x]=INF;
			
			w[1]=0;
			pq.push(ii(w[1],1));
			while (!pq.empty()){
				temp=pq.top().first;
				node=pq.top().second;
				pq.pop();
				if (temp>w[node]) continue; //important
				for (auto &it:al[node]){
					if (it.id==it2.first) continue;
					if (w[it.v]>w[node]+it.len){
						w[it.v]=w[node]+it.len;
						pq.push(ii (w[it.v],it.v));
					}
				}
			}
			it2.second=w[n];
		}
	}
	
	//find the path on best line from T->S
	if (tf[1]!=INF){
		int curr=1;
		
		while (curr!=n){
			//debug(pt[curr]);
			sp_b[pt[curr]]=INF;
			curr=edges[pt[curr]].u;
		}
		
		for (auto &it2:sp_b) {
			//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;
			
			rep(x,0,205) w[x]=INF;
			
			w[n]=0;
			pq.push(ii(w[n],n));
			while (!pq.empty()){
				temp=pq.top().first;
				node=pq.top().second;
				pq.pop();
				if (temp>w[node]) continue; //important
				for (auto &it:al[node]){
					if (it.id==it2.first) continue;
					if (w[it.v]>w[node]+it.len){
						w[it.v]=w[node]+it.len;
						pq.push(ii (w[it.v],it.v));
					}
				}
			}

			it2.second=w[1];
		}
	}
}

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();
	
	SP_d();
	
	//try dijk start and end
	ll ans=sf[n]+tf[1];
	
	for (auto &it:edges){
		ans=min(ans,(sp_f.count(it.id)?sp_f[it.id]:min(sf[n],sf[it.v]+tb[it.u]+it.len))+(sp_b.count(it.id)?sp_b[it.id]:min(tf[1],tf[it.v]+sb[it.u]+it.len))+it.flip);
		//debug(min((sp_f.count(it.id)?sp_f[it.id]:sf[n]),sf[it.v]+tb[it.u]+it.len));
		//debug(min((sp_b.count(it.id)?sp_b[it.id]:tf[1]),tf[it.v]+sb[it.u]+it.len));
	}
	
	if (ans>=INF) cout<<-1<<endl;
	else cout<<ans<<endl;
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 6 ms 512 KB Output is correct
4 Correct 6 ms 512 KB Output is correct
5 Correct 5 ms 512 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 512 KB Output is correct
10 Correct 20 ms 512 KB Output is correct
11 Correct 20 ms 512 KB Output is correct
12 Correct 20 ms 512 KB Output is correct
13 Correct 5 ms 512 KB Output is correct
14 Correct 6 ms 512 KB Output is correct
15 Correct 5 ms 512 KB Output is correct
16 Correct 6 ms 512 KB Output is correct

Subtask #2
11.0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 33 ms 7144 KB Output is correct
2 Correct 33 ms 7012 KB Output is correct
3 Correct 33 ms 6896 KB Output is correct
4 Correct 7 ms 640 KB Output is correct
5 Correct 5 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 4 ms 384 KB Output is correct
9 Correct 31 ms 7024 KB Output is correct
10 Correct 33 ms 7016 KB Output is correct
11 Correct 35 ms 6768 KB Output is correct
12 Correct 33 ms 7016 KB Output is correct
13 Correct 33 ms 6760 KB Output is correct
14 Correct 34 ms 7528 KB Output is correct

Subtask #3
21.0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 5 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 24 ms 6132 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 30 ms 6760 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 30 ms 7408 KB Output is correct
9 Correct 28 ms 7792 KB Output is correct
10 Correct 29 ms 7408 KB Output is correct
11 Correct 31 ms 7524 KB Output is correct
12 Correct 30 ms 7656 KB Output is correct
13 Correct 5 ms 384 KB Output is correct
14 Correct 4 ms 384 KB Output is correct
15 Correct 4 ms 384 KB Output is correct
16 Correct 5 ms 384 KB Output is correct
17 Correct 4 ms 384 KB Output is correct
18 Correct 4 ms 384 KB Output is correct
19 Correct 28 ms 7792 KB Output is correct
20 Correct 29 ms 7536 KB Output is correct
21 Correct 29 ms 7656 KB Output is correct
22 Correct 29 ms 7400 KB Output is correct

Subtask #4
63.0 / 63.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 512 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 6 ms 512 KB Output is correct
4 Correct 6 ms 512 KB Output is correct
5 Correct 5 ms 512 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 5 ms 512 KB Output is correct
10 Correct 20 ms 512 KB Output is correct
11 Correct 20 ms 512 KB Output is correct
12 Correct 20 ms 512 KB Output is correct
13 Correct 5 ms 512 KB Output is correct
14 Correct 6 ms 512 KB Output is correct
15 Correct 5 ms 512 KB Output is correct
16 Correct 6 ms 512 KB Output is correct
17 Correct 33 ms 7144 KB Output is correct
18 Correct 33 ms 7012 KB Output is correct
19 Correct 33 ms 6896 KB Output is correct
20 Correct 7 ms 640 KB Output is correct
21 Correct 5 ms 512 KB Output is correct
22 Correct 5 ms 384 KB Output is correct
23 Correct 5 ms 384 KB Output is correct
24 Correct 4 ms 384 KB Output is correct
25 Correct 31 ms 7024 KB Output is correct
26 Correct 33 ms 7016 KB Output is correct
27 Correct 35 ms 6768 KB Output is correct
28 Correct 33 ms 7016 KB Output is correct
29 Correct 33 ms 6760 KB Output is correct
30 Correct 34 ms 7528 KB Output is correct
31 Correct 5 ms 512 KB Output is correct
32 Correct 5 ms 384 KB Output is correct
33 Correct 24 ms 6132 KB Output is correct
34 Correct 5 ms 384 KB Output is correct
35 Correct 30 ms 6760 KB Output is correct
36 Correct 4 ms 384 KB Output is correct
37 Correct 5 ms 384 KB Output is correct
38 Correct 30 ms 7408 KB Output is correct
39 Correct 28 ms 7792 KB Output is correct
40 Correct 29 ms 7408 KB Output is correct
41 Correct 31 ms 7524 KB Output is correct
42 Correct 30 ms 7656 KB Output is correct
43 Correct 5 ms 384 KB Output is correct
44 Correct 4 ms 384 KB Output is correct
45 Correct 4 ms 384 KB Output is correct
46 Correct 5 ms 384 KB Output is correct
47 Correct 4 ms 384 KB Output is correct
48 Correct 4 ms 384 KB Output is correct
49 Correct 28 ms 7792 KB Output is correct
50 Correct 29 ms 7536 KB Output is correct
51 Correct 29 ms 7656 KB Output is correct
52 Correct 29 ms 7400 KB Output is correct
53 Correct 35 ms 7536 KB Output is correct
54 Correct 35 ms 7536 KB Output is correct
55 Correct 37 ms 7544 KB Output is correct
56 Correct 6 ms 512 KB Output is correct
57 Correct 6 ms 512 KB Output is correct
58 Correct 91 ms 6772 KB Output is correct
59 Correct 94 ms 6772 KB Output is correct
60 Correct 97 ms 6772 KB Output is correct
61 Correct 78 ms 6900 KB Output is correct
62 Correct 92 ms 6772 KB Output is correct
63 Correct 102 ms 6764 KB Output is correct
64 Correct 661 ms 6388 KB Output is correct
65 Correct 640 ms 6516 KB Output is correct
66 Correct 590 ms 6516 KB Output is correct
67 Correct 23 ms 5600 KB Output is correct
68 Correct 33 ms 8040 KB Output is correct
69 Correct 32 ms 8040 KB Output is correct
70 Correct 33 ms 7656 KB Output is correct
71 Correct 36 ms 7656 KB Output is correct
72 Correct 32 ms 7908 KB Output is correct
73 Correct 35 ms 7912 KB Output is correct
74 Correct 36 ms 8040 KB Output is correct