oj.uz

Submission #898550

# Submission time Handle Problem Language Result Execution time Memory
898550 2024-01-04T21:31:09 Z Mathias Valley (BOI19_valley) C++14
100 / 100
 147 ms 49452 KB 
#include <bits/stdc++.h>
using namespace std;
#define ll long long
const ll INF = 1e18;
const ll MAXN = 1e5+7;
const ll LOG = 18;
struct str{
	ll fi,sc;
};
int pre[MAXN];
int post[MAXN];
ll wo[MAXN];
int depth[MAXN];
int degree[MAXN];
int ojciec[MAXN];
ll dis[MAXN];
ll suma[MAXN];
bool visited[MAXN];
str jp[MAXN][LOG];
pair<int,int> in[MAXN];
vector<pair<int,ll> > g[MAXN];
queue<int> que;
ll w,diff,cnt=0;
void DFS(int x,int f,ll d){
	pre[x]=++cnt;
	depth[x]=depth[f]+1;
	suma[x]=suma[f]+d;
	jp[x][0]={f,min(dis[f]+wo[x],dis[x])};
	//cout<<jp[x][0].sc<<'\n';
	for(ll i=1;i<LOG;i++){
		jp[x][i].fi=jp[jp[x][i-1].fi][i-1].fi;
		jp[x][i].sc=min(jp[x][i-1].sc,jp[jp[x][i-1].fi][i-1].sc-suma[jp[x][i-1].fi]+suma[x]);
		//cout<<x<<' '<<i<<' '<<jp[x][i-1].sc<<' '<<jp[jp[x][i-1].fi][i-1].sc<<' '<<suma[jp[x][i-1].fi]<<' '<<suma[x]<<' '<<jp[x][i].sc<<'\n';
	}
	for(auto sas:g[x]){
		if(f==sas.first) continue;
		DFS(sas.first, x, sas.second);
	}
	post[x]=++cnt;
}
bool anc(int a,int b){
	return (pre[a] <= pre[b] && post[a] >= post[b]);
}
void DFS1(int x,int f){
	visited[x]=1;
	ojciec[x]=f;
	for(ll i=0;i<g[x].size();i++){
		if(g[x][i].first==f) wo[x]=g[x][i].second;
		if(!visited[g[x][i].first]){
			DFS1(g[x][i].first, x);
		}
	}
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll n,q,s,r,sk,a,b,x,y,b1,res=INF,c;
	cin>>n>>s>>q>>r;
	for(int i=1;i<n;i++){
		cin>>a>>b>>c;
		in[i]={a,b};
		g[a].push_back({b,c});
		g[b].push_back({a,c});
		degree[a]++;
		degree[b]++;
	}
	for(ll i=1;i<=n;i++){
		if(degree[i]==1 and i!=r) que.push(i); 
		dis[i]=INF;	
	} 
	for(ll i=1;i<=s;i++){
		cin>>sk;
		dis[sk]=0;
	}
	for(ll i=1;i<=n;i++) visited[i]=0;
	DFS1(r,0);
	while(!que.empty()){
		x=que.front();
		que.pop();
		dis[ojciec[x]]=min(dis[ojciec[x]], dis[x]+wo[x]);
		degree[ojciec[x]]--;
		if(degree[ojciec[x]]<=1 and ojciec[x]!=0) que.push(ojciec[x]);
	}
	DFS(r,r,0);
	while(q--){
		cin>>a>>b;
		x=in[a].first;
		y=in[a].second;
		if(depth[x]>depth[y]) swap(x,y);
		if(anc(y,b)==false){
			cout<<"escaped\n";
			continue;
		}
		res=dis[b];
		b1=b;
		for(int i=LOG-1;i>=0;i--){
			if(depth[jp[b][i].fi]<depth[y]) continue;
			if(jp[b][i].sc-suma[b]+suma[b1]<res){
				res=jp[b][i].sc-suma[b]+suma[b1];
			} 
			//cout<<b<<' '<<mini<<'\n';
			b=jp[b][i].fi;
		}
		if(res==INF) cout<<"oo\n";
		else cout<<res<<'\n';
	}
	return 0;
}

Compilation message

valley.cpp: In function 'void DFS1(int, int)':
valley.cpp:47:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |  for(ll i=0;i<g[x].size();i++){
      |             ~^~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8796 KB Output is correct
2 Correct 3 ms 8796 KB Output is correct
3 Correct 3 ms 8796 KB Output is correct
4 Correct 3 ms 8796 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8796 KB Output is correct
2 Correct 3 ms 8796 KB Output is correct
3 Correct 3 ms 8796 KB Output is correct
4 Correct 3 ms 8796 KB Output is correct
5 Correct 2 ms 8924 KB Output is correct
6 Correct 2 ms 8924 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 2 ms 8796 KB Output is correct
9 Correct 2 ms 8796 KB Output is correct
10 Correct 2 ms 8796 KB Output is correct
11 Correct 3 ms 9048 KB Output is correct
12 Correct 2 ms 8796 KB Output is correct
13 Correct 2 ms 8796 KB Output is correct
14 Correct 2 ms 8796 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 109 ms 45752 KB Output is correct
2 Correct 113 ms 45392 KB Output is correct
3 Correct 118 ms 45504 KB Output is correct
4 Correct 147 ms 47068 KB Output is correct
5 Correct 120 ms 47384 KB Output is correct
6 Correct 142 ms 48724 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 8796 KB Output is correct
2 Correct 3 ms 8796 KB Output is correct
3 Correct 3 ms 8796 KB Output is correct
4 Correct 3 ms 8796 KB Output is correct
5 Correct 2 ms 8924 KB Output is correct
6 Correct 2 ms 8924 KB Output is correct
7 Correct 2 ms 8796 KB Output is correct
8 Correct 2 ms 8796 KB Output is correct
9 Correct 2 ms 8796 KB Output is correct
10 Correct 2 ms 8796 KB Output is correct
11 Correct 3 ms 9048 KB Output is correct
12 Correct 2 ms 8796 KB Output is correct
13 Correct 2 ms 8796 KB Output is correct
14 Correct 2 ms 8796 KB Output is correct
15 Correct 109 ms 45752 KB Output is correct
16 Correct 113 ms 45392 KB Output is correct
17 Correct 118 ms 45504 KB Output is correct
18 Correct 147 ms 47068 KB Output is correct
19 Correct 120 ms 47384 KB Output is correct
20 Correct 142 ms 48724 KB Output is correct
21 Correct 101 ms 45440 KB Output is correct
22 Correct 110 ms 45476 KB Output is correct
23 Correct 107 ms 45252 KB Output is correct
24 Correct 128 ms 46968 KB Output is correct
25 Correct 138 ms 49420 KB Output is correct
26 Correct 96 ms 45384 KB Output is correct
27 Correct 104 ms 45080 KB Output is correct
28 Correct 113 ms 45396 KB Output is correct
29 Correct 125 ms 46672 KB Output is correct
30 Correct 144 ms 47824 KB Output is correct
31 Correct 93 ms 45648 KB Output is correct
32 Correct 116 ms 45396 KB Output is correct
33 Correct 114 ms 45396 KB Output is correct
34 Correct 136 ms 47076 KB Output is correct
35 Correct 130 ms 49452 KB Output is correct
36 Correct 128 ms 47036 KB Output is correct