oj.uz

Submission #778027

# Submission time Handle Problem Language Result Execution time Memory
778027 2023-07-10T03:27:20 Z mars4 Valley (BOI19_valley) C++17
100 / 100
 173 ms 33272 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 ff              first
#define ss              second
#define ll              int64_t
#define ld              long double
#define nl              cout<<"\n"
#define i128            __int128_t
#define all(v)          v.begin(),v.end()
#define mset(a,v)       memset((a),(v),sizeof(a))
#define forn(i,a,b)     for(int64_t i=int64_t(a);i<int64_t(b);++i)
#define forb(i,a,b)     for(int64_t i=int64_t(a);i>=int64_t(b);--i)
#define fastio()        ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

#define mod         1'000'000'007
#define mod2        998'244'353 
#define inf         1'000'000'000'000'007
#define pi          3.14159265358979323846

template<class key,class cmp=std::less<key>>
using ordered_set=tree<key,null_type,cmp,rb_tree_tag,tree_order_statistics_node_update>;

template<class L,class R> ostream& operator<<(ostream& out,pair<L,R> &p)        {return out<<"("<<p.ff<<", "<<p.ss<<")";}
template<class T> ostream& operator<<(ostream& out,vector<T> &v)                {out<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())out<<", ";out<<*it;}return out<<"]";}
template<class T> ostream& operator<<(ostream& out,deque<T> &v)                 {out<<"[";for(auto it=v.begin();it!=v.end();++it){if(it!=v.begin())out<<", ";out<<*it;}return out<<"]";}
template<class T> ostream& operator<<(ostream& out,set<T> &s)                   {out<<"{";for(auto it=s.begin();it!=s.end();++it){if(it!=s.begin())out<<", ";out<<*it;}return out<<"}";}
template<class T> ostream& operator<<(ostream& out,ordered_set<T> &s)           {out<<"{";for(auto it=s.begin();it!=s.end();++it){if(it!=s.begin())out<<", ";out<<*it;}return out<<"}";}
template<class L,class R> ostream& operator<<(ostream& out,map<L,R> &m)         {out<<"{";for(auto it=m.begin();it!=m.end();++it){if(it!=m.begin())out<<", ";out<<*it;}return out<<"}";}

void dbg_out() {cerr<<"]\n";}
template<typename Head,typename... Tail> 
void dbg_out(Head H,Tail... T) {cerr<<H;if(sizeof...(Tail))cerr<<", ";dbg_out(T...);}
#ifdef LOCAL
#define dbg(...) cerr<<"["<<#__VA_ARGS__<<"] = [",dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

//---------------------------------mars4---------------------------------

vector<vector<ll>> v;
vector<vector<pair<ll,ll>>> g;
vector<ll> dist;

void dfs(ll cur,ll prev)
{
	for(auto [nxt,w]:g[cur])
	{
		if(nxt!=prev)
		{
			dist[nxt]=dist[cur]+w;
			dfs(nxt,cur);
		}
	}
}

class SegtreeMin
{
	ll N;
	
	public:
	vector<ll> segtree;

	void init(ll n,ll val=0)
	{
		N=n;
		segtree=vector<ll>(N<<1,val);
	}

	void build(vector<ll> &a)
	{
		forn(i,0,N)
			segtree[i+N]=a[i];
		forb(i,N-1,1)
			segtree[i]=min(segtree[i<<1],segtree[i<<1|1]);
	}

	void update(ll i,ll val)
	{
		if(segtree[i+N]>val)
		{
			for(segtree[i+=N]=val;i>>=1;)
				segtree[i]=min(segtree[i<<1],segtree[i<<1|1]);
		}
	}

	ll query(ll l,ll r)
	{
		ll res=2*inf;
		for(l+=N,r+=N+1;l<r;l>>=1,r>>=1)
		{
			if(l&1) res=min(res,segtree[l++]);
			if(r&1) res=min(res,segtree[--r]);
		}
		return res;
	}
};

class HLD
{
	ll N;
	ll timer;

	void dfs_sz(ll cur,ll prev,vector<vector<ll>> &v)
	{
		child[cur]=1;
		parent[cur]=prev;
		for(ll i:v[cur])
		{
			if(i!=prev)
			{
				depth[i]=depth[cur]+1;
				dfs_sz(i,cur,v);
				child[cur]+=child[i];
			}
		}
	}

	void dfs_hld(ll cur,ll prev,ll top,vector<vector<ll>> &v)
	{
		timer++;
		st[cur]=timer;
		tp[cur]=top;
		dn[top]=cur;
		ll h_ind=-1,h_sz=-1;
		for(ll i=0;i<(ll)v[cur].size();i++)
		{
			if(v[cur][i]!=prev)
			{
				if(child[v[cur][i]]>h_sz)
				{
					h_ind=i;
					h_sz=child[v[cur][i]];
				}
			}
		}
		if(h_ind==-1)
		{
			ed[cur]=timer;
			return;
		}
		swap(v[cur][0],v[cur][h_ind]);
		dfs_hld(v[cur][0],cur,top,v);
		for(ll i:v[cur])
		{
			if(i!=prev and i!=v[cur][0])
			{
				dfs_hld(i,cur,i,v);
			}
		}
		ed[cur]=timer;
	}

	public:
	vector<ll> child;
	vector<ll> parent;
	vector<ll> depth;
	vector<ll> st;
	vector<ll> ed;
	vector<ll> tp;
	vector<ll> dn;

	// use segtree class
	SegtreeMin s_down;
	SegtreeMin s_up;

	void init(vector<vector<ll>> &v,ll root=0)
	{
		N=(ll)v.size();
		s_down.init(N,2*inf);
		s_up.init(N,2*inf);
		child=vector<ll>(N);
		parent=vector<ll>(N);
		depth=vector<ll>(N);
		st=vector<ll>(N);
		ed=vector<ll>(N);
		tp=vector<ll>(N);
		dn=vector<ll>(N);
		timer=-1;
		dfs_sz(root,root,v);
		dfs_hld(root,root,root,v);
	}

	void update(ll node)
	{
		ll cur=node;
		while(true)
		{
			s_down.update(st[cur],dist[node]);
			s_up.update(st[cur],dist[node]-2*dist[cur]);
			ll ncur=parent[tp[cur]];
			if(cur==ncur)
			{
				break;
			}
			cur=ncur;
		}
	}

	// use appropriate query operation (vertex/edge)
	ll query(ll node,ll cut)
	{
		ll cur=node;
		ll res=inf;
		while(depth[tp[cur]]>depth[cut])
		{
			ll up_val=s_up.query(st[tp[cur]],st[cur])+dist[node];
			ll down_val=s_down.query(st[cur],st[dn[tp[cur]]])+dist[node]-2*dist[cur];
			res=min({res,up_val,down_val});
			cur=parent[tp[cur]];
		}
		ll up_val=s_up.query(st[cut],st[cur])+dist[node];
		ll down_val=s_down.query(st[cur],st[dn[tp[cur]]])+dist[node]-2*dist[cur];
		res=min({res,up_val,down_val});
		return res;
	}
};

int main()
{
	fastio();
	ll z,n,m,t,k,i,j,l,d,h,r;
	ll q,root;
	cin>>n>>m>>q>>root;
	root--;
	v=vector<vector<ll>>(n);
	g=vector<vector<pair<ll,ll>>>(n);
	dist=vector<ll>(n);
	vector<pair<ll,ll>> edges(n-1);
	forn(i,0,n-1)
	{
		cin>>l>>r>>d;
		l--,r--;
		v[l].push_back(r);
		v[r].push_back(l);
		g[l].push_back({r,d});
		g[r].push_back({l,d});
		edges[i]={l,r};
	}
	dfs(root,-1);
	HLD hld;
	hld.init(v,root);
	forn(i,0,m)
	{
		cin>>d;
		hld.update(d-1);
	}
	forn(i,0,q)
	{
		cin>>k>>d;
		k--,d--;
		auto [l,r]=edges[k];
		if(hld.depth[l]<hld.depth[r])
		{
			swap(l,r);
		}
		if(hld.st[l]<=hld.st[d] and hld.ed[l]>=hld.st[d])
		{
			ll res=hld.query(d,l);
			if(res==inf)
			{
				cout<<"oo\n";
			}
			else
			{
				cout<<res<<"\n";
			}
		}
		else
		{
			cout<<"escaped\n";
		}
	}
	cerr<<"\nTime elapsed: "<<1000*clock()/CLOCKS_PER_SEC<<"ms\n";
	return 0;
}

Compilation message

valley.cpp: In function 'int main()':
valley.cpp:227:5: warning: unused variable 'z' [-Wunused-variable]
  227 |  ll z,n,m,t,k,i,j,l,d,h,r;
      |     ^
valley.cpp:227:11: warning: unused variable 't' [-Wunused-variable]
  227 |  ll z,n,m,t,k,i,j,l,d,h,r;
      |           ^
valley.cpp:227:15: warning: unused variable 'i' [-Wunused-variable]
  227 |  ll z,n,m,t,k,i,j,l,d,h,r;
      |               ^
valley.cpp:227:17: warning: unused variable 'j' [-Wunused-variable]
  227 |  ll z,n,m,t,k,i,j,l,d,h,r;
      |                 ^
valley.cpp:227:23: warning: unused variable 'h' [-Wunused-variable]
  227 |  ll z,n,m,t,k,i,j,l,d,h,r;
      |                       ^

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 468 KB Output is correct
2 Correct 2 ms 456 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 468 KB Output is correct
2 Correct 2 ms 456 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
7 Correct 1 ms 596 KB Output is correct
8 Correct 1 ms 584 KB Output is correct
9 Correct 1 ms 596 KB Output is correct
10 Correct 1 ms 596 KB Output is correct
11 Correct 2 ms 596 KB Output is correct
12 Correct 1 ms 596 KB Output is correct
13 Correct 1 ms 596 KB Output is correct
14 Correct 1 ms 596 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 149 ms 29604 KB Output is correct
2 Correct 141 ms 29260 KB Output is correct
3 Correct 152 ms 29204 KB Output is correct
4 Correct 173 ms 30924 KB Output is correct
5 Correct 144 ms 31040 KB Output is correct
6 Correct 147 ms 32828 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 468 KB Output is correct
2 Correct 2 ms 456 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 2 ms 468 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
7 Correct 1 ms 596 KB Output is correct
8 Correct 1 ms 584 KB Output is correct
9 Correct 1 ms 596 KB Output is correct
10 Correct 1 ms 596 KB Output is correct
11 Correct 2 ms 596 KB Output is correct
12 Correct 1 ms 596 KB Output is correct
13 Correct 1 ms 596 KB Output is correct
14 Correct 1 ms 596 KB Output is correct
15 Correct 149 ms 29604 KB Output is correct
16 Correct 141 ms 29260 KB Output is correct
17 Correct 152 ms 29204 KB Output is correct
18 Correct 173 ms 30924 KB Output is correct
19 Correct 144 ms 31040 KB Output is correct
20 Correct 147 ms 32828 KB Output is correct
21 Correct 96 ms 29208 KB Output is correct
22 Correct 107 ms 28568 KB Output is correct
23 Correct 118 ms 28636 KB Output is correct
24 Correct 121 ms 30548 KB Output is correct
25 Correct 132 ms 33272 KB Output is correct
26 Correct 103 ms 29220 KB Output is correct
27 Correct 133 ms 28604 KB Output is correct
28 Correct 126 ms 28760 KB Output is correct
29 Correct 120 ms 30060 KB Output is correct
30 Correct 120 ms 31436 KB Output is correct
31 Correct 115 ms 29260 KB Output is correct
32 Correct 125 ms 28748 KB Output is correct
33 Correct 157 ms 28872 KB Output is correct
34 Correct 129 ms 30532 KB Output is correct
35 Correct 113 ms 33116 KB Output is correct
36 Correct 160 ms 30540 KB Output is correct