oj.uz

Submission #201140

# Submission time Handle Problem Language Result Execution time Memory
201140 2020-02-09T12:13:52 Z zscoder Olympic Bus (JOI20_ho_t4) C++17
16 / 100
 1000 ms 10392 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
set<int> S;

struct Graph
{
	struct edge
	{
		int v; ll weight; int id;
	};
	vector<vector<edge> > adj;
	int n;
	
	Graph(int _n)
	{
		adj.resize(_n);
		n = _n;
	}
	
	void addedge(int u, int v, ll c, int id)
	{
		edge tmp;
		tmp.v = v; tmp.weight = c; tmp.id=id;
		adj[u].pb(tmp);
	}
	
	void reset()
	{
		adj.clear();
	}
	
	vector<ll> dist;
	vi par;
	
	void bfs(int s)
	{
		ll INFI = ll(1e18);
		dist.assign(n, INFI);
		par.assign(n, -1);
		dist[s] = 0; par[s] = -1;
		queue<int> q; q.push(s);
		while(!q.empty())
		{
			int u = q.front(); q.pop();
			for(int i = 0; i < adj[u].size(); i++)
			{
				int v = adj[u][i].v;
				if(dist[v] >= INFI)
				{
					dist[v] = dist[u] + 1;
					par[v] = u;
					q.push(v);
				}
			}
		}
	}
	
	void bfs01(int s)
	{
		ll INFI = ll(1e18);
		dist.assign(n, INFI);
		par.assign(n, -1);
		dist[s] = 0; par[s] = -1;
		deque<int> q; q.pb(s);
		while(!q.empty())
		{
			int u = q.front(); q.pop_front();
			for(int i = 0; i < adj[u].size(); i++)
			{
				int v = adj[u][i].v; ll w = adj[u][i].weight;
				if(dist[v] >= INFI)
				{
					if(w == 1)
					{
						dist[v] = dist[u] + 1;
						par[v] = u;
						q.push_back(v);
					}
					else
					{
						dist[v] = dist[u];
						par[v] = u;
						q.push_front(v);
					}
				}
			}
		}
	}
	
	void dijkstra(int s, int mode=1)
	{
		ll INFI = ll(1e18);
		dist.clear();
		dist.assign(n, INFI);
		par.assign(n, -1);
		dist[s] = 0; par[s] = -1;
		priority_queue<ii, vector<ii>, greater<ii> > pq;
		pq.push(ii(0, s));
		while(!pq.empty())
		{
			int u = pq.top().se; ll d = pq.top().fi; pq.pop();
			for(int i = 0; i < adj[u].size(); i++)
			{
				int v = adj[u][i].v; ll w = adj[u][i].weight;
				if(d + w < dist[v])
				{
					dist[v] = d + w;
					par[v] = u;
					//cerr<<"ADD "<<adj[u][i].id<<'\n';
					if(mode) S.insert(adj[u][i].id);
					pq.push(ii(dist[v], v));
				}
			}
		}
	}
	
	vector<vector<ll> > d;
	
	void Floyd()
	{
		ll INFIN = ll(1e18);
		d.resize(n);
		for(int i = 0; i < n; i++)
		{
			d[i].assign(n, INFIN);
		}
		for(int i = 0; i < n; i++)
		{
			for(int j = 0; j < adj[i].size(); j++)
			{
				d[i][adj[i][j].v] = min(d[i][adj[i][j].v],adj[i][j].weight);
			}
			d[i][i] = 0;
		}
		for(int k = 0; k < n; k++)
		{
			for(int i = 0; i < n; i++)
			{
				for(int j = 0; j < n; j++)
				{
					d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
				}
			}
		}
	}
};

ll D[55555];
vector<pair<ii,ii> > edges;
int n,m; 
ll res=ll(1e18);

void test(int id)
{
	Graph G(n);
	for(int i=0;i<m;i++)
	{
		int u=edges[i].fi.fi; int v=edges[i].fi.se;
		if(i==id) swap(u,v);
		G.addedge(u,v,edges[i].se.fi,edges[i].se.se);
	}
	G.dijkstra(0,0);
	ll ans = G.dist[n-1];
	G.dijkstra(n-1,0);
	ans+=G.dist[0];
	ans+=D[id];
	res=min(res,ans);
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin>>n>>m;
	Graph ori(n),oriunw(n);
	vector<ii> VV;
	int all0=1;
	map<ii,ii> ma;
	for(int i=0;i<m;i++)
	{
		int u,v,c,d;
		cin>>u>>v>>c>>d;
		if(c!=0) all0=0;
		VV.pb({d,i});
		u--; v--;
		if(ma.find({u,v})==ma.end())
		{
			ma[{u,v}]={c+d,i};
		}
		else
		{
			ma[{u,v}]=min(ma[{u,v}],{c+d,i});
		}
		D[i]=d;
		edges.pb({{u,v},{c,d}});
		ori.addedge(u,v,c,i);
		oriunw.addedge(u,v,c,i);
		oriunw.addedge(v,u,c+d,i);
	}
	int sub2=1;
	if(m%2==0)
	{
		for(int i=0;i<m;i+=2)
		{
			int a1 = edges[i].se.se;
			int a2 = edges[i+1].se.se;
			edges[i].se.se=edges[i+1].se.se=0;
			if(edges[i]!=edges[i+1]) sub2=0;
			edges[i].se.se=a1; edges[i+1].se.se=a2;
		}
	}
	else sub2=0;
	ori.Floyd();
	//ori.dijkstra(0);
	sort(VV.begin(),VV.end());
	//for(int i=0;i<min(100,m);i++) S.insert(VV[i].se);
	//ll as = ori.dist[n-1];
	//ori.dijkstra(n-1);
	//as+=ori.dist[0];
	ll as = ori.d[0][n-1]+ori.d[n-1][0];
	oriunw.dijkstra(0);
	oriunw.dijkstra(n-1);
	res=min(res,as);
	//test(ma[{141,15}].se);
	//assert(sub2);
	if(sub2)
	{
		for(auto E:edges)
		{
			int u=E.fi.fi; int v=E.fi.se; 
			ll c=E.se.fi; ll d=E.se.se;
			//should i add the edge v->u
			res=min(res,d+ori.d[0][n-1]+ori.d[n-1][v]+c+ori.d[u][0]);
			res=min(res,d+ori.d[0][v]+c+ori.d[u][n-1]+ori.d[n-1][0]);
			res=min(res,d+ori.d[0][v]+c+ori.d[u][n-1]+ori.d[n-1][v]+c+ori.d[u][0]);
			res=min(res,ori.d[0][n-1]+ori.d[n-1][0]);
		}
	}
	else
	{
		/*
		vi nw;
		for(int s:S)
		{
			int u=edges[s].fi.fi; int v=edges[s].fi.se;
			nw.pb(ma[{u,v}].se);
		}
		*/
		for(int s:S) 
		{
			test(s);
		}
	}
	if(res>=ll(1e18)) res=-1;
	cout<<res<<'\n';
}

Compilation message

ho_t4.cpp: In member function 'void Graph::bfs(int)':
ho_t4.cpp:62:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < adj[u].size(); i++)
                   ~~^~~~~~~~~~~~~~~
ho_t4.cpp: In member function 'void Graph::bfs01(int)':
ho_t4.cpp:85:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < adj[u].size(); i++)
                   ~~^~~~~~~~~~~~~~~
ho_t4.cpp: In member function 'void Graph::dijkstra(int, int)':
ho_t4.cpp:119:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < adj[u].size(); i++)
                   ~~^~~~~~~~~~~~~~~
ho_t4.cpp: In member function 'void Graph::Floyd()':
ho_t4.cpp:146:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j = 0; j < adj[i].size(); j++)
                   ~~^~~~~~~~~~~~~~~
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:193:6: warning: variable 'all0' set but not used [-Wunused-but-set-variable]
  int all0=1;
      ^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 1016 KB Output is correct
2 Correct 18 ms 760 KB Output is correct
3 Correct 85 ms 888 KB Output is correct
4 Correct 93 ms 888 KB Output is correct
5 Correct 17 ms 504 KB Output is correct
6 Correct 21 ms 888 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 6 ms 504 KB Output is correct
10 Correct 121 ms 888 KB Output is correct
11 Correct 124 ms 888 KB Output is correct
12 Correct 215 ms 1016 KB Output is correct
13 Correct 67 ms 888 KB Output is correct
14 Correct 77 ms 888 KB Output is correct
15 Correct 72 ms 888 KB Output is correct
16 Correct 68 ms 1016 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 8012 KB Output is correct
2 Correct 74 ms 7912 KB Output is correct
3 Correct 71 ms 7860 KB Output is correct
4 Correct 16 ms 1016 KB Output is correct
5 Correct 18 ms 888 KB Output is correct
6 Correct 15 ms 892 KB Output is correct
7 Correct 14 ms 760 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 72 ms 8036 KB Output is correct
10 Correct 75 ms 8168 KB Output is correct
11 Correct 71 ms 7780 KB Output is correct
12 Correct 69 ms 7652 KB Output is correct
13 Correct 73 ms 7656 KB Output is correct
14 Correct 72 ms 8552 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 892 KB Output is correct
2 Correct 19 ms 760 KB Output is correct
3 Correct 913 ms 8696 KB Output is correct
4 Correct 19 ms 760 KB Output is correct
5 Execution timed out 1093 ms 10392 KB Time limit exceeded
6 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 1016 KB Output is correct
2 Correct 18 ms 760 KB Output is correct
3 Correct 85 ms 888 KB Output is correct
4 Correct 93 ms 888 KB Output is correct
5 Correct 17 ms 504 KB Output is correct
6 Correct 21 ms 888 KB Output is correct
7 Correct 5 ms 376 KB Output is correct
8 Correct 5 ms 376 KB Output is correct
9 Correct 6 ms 504 KB Output is correct
10 Correct 121 ms 888 KB Output is correct
11 Correct 124 ms 888 KB Output is correct
12 Correct 215 ms 1016 KB Output is correct
13 Correct 67 ms 888 KB Output is correct
14 Correct 77 ms 888 KB Output is correct
15 Correct 72 ms 888 KB Output is correct
16 Correct 68 ms 1016 KB Output is correct
17 Correct 71 ms 8012 KB Output is correct
18 Correct 74 ms 7912 KB Output is correct
19 Correct 71 ms 7860 KB Output is correct
20 Correct 16 ms 1016 KB Output is correct
21 Correct 18 ms 888 KB Output is correct
22 Correct 15 ms 892 KB Output is correct
23 Correct 14 ms 760 KB Output is correct
24 Correct 5 ms 376 KB Output is correct
25 Correct 72 ms 8036 KB Output is correct
26 Correct 75 ms 8168 KB Output is correct
27 Correct 71 ms 7780 KB Output is correct
28 Correct 69 ms 7652 KB Output is correct
29 Correct 73 ms 7656 KB Output is correct
30 Correct 72 ms 8552 KB Output is correct
31 Correct 55 ms 892 KB Output is correct
32 Correct 19 ms 760 KB Output is correct
33 Correct 913 ms 8696 KB Output is correct
34 Correct 19 ms 760 KB Output is correct
35 Execution timed out 1093 ms 10392 KB Time limit exceeded
36 Halted 0 ms 0 KB -