oj.uz

Submission #129925

# Submission time Handle Problem Language Result Execution time Memory
129925 2019-07-13T14:36:35 Z rajarshi_basu Valley (BOI19_valley) C++14
100 / 100
 347 ms 43844 KB 
#include <iostream>
#include <vector>
#include <set>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <stdio.h>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <fstream>
#include <complex>
#include <random>
#include <stack>
#include <chrono>
#include <set>

#define FOR(i,n) for(int i=0;i<n;i++)
#define FORE(i,a,b) for(int i=a;i<=b;i++)
#define ll long long int
#define vi vector<int>
#define ii pair<int,int>
#define pb push_back
#define mp make_pair
#define ff first
#define il pair<int,ll>
#define li pair<ll,int>
#define ss second
#define pll pair<ll,ll>
#define cd complex<double> 
#define ld long double
#define pld pair<ld,ld>
#define iii pair<ii,ll>
#define vv vector

using namespace std;

const ll INF = 1e16+10;
const int MAXN = 100*100*10+10;
const int B = 430;

int n,e,s;
bool sp[MAXN];
vi special;
vv<il> g[MAXN];
vv<iii> edges;

int parent[20][MAXN];
ll dist[MAXN];
int dpt[MAXN];
int st[MAXN];
int en[MAXN];
int T = -1;
void dfs1(int node,int p = -1){
	parent[0][node] = p;
	dpt[node] = (p==-1)?0:dpt[p]+1;
	st[node] = ++T; 
	for(auto e : g[node]){
		if(e.ff == p)continue;
		dist[e.ff] = dist[node] + e.ss;
		dfs1(e.ff,node);

	}
	en[node] = ++T;
}

ll dist2[20][MAXN];
void dfs2(int node,int p=-1){
	if(sp[node])dist2[0][node] = dist[node];
	else dist2[0][node] = 10*INF;

	for(auto e  : g[node]){
		if(e.ff == p)continue;
		dfs2(e.ff,node);
		dist2[0][node] = min(dist2[0][node],dist2[0][e.ff]);
	}
	
}

void computeSparseTable(){

	FORE(j,1,19){
		FOR(i,n){
			int x = parent[j-1][i];
			if(x == -1)parent[j][i] = -1;
			else parent[j][i] = parent[j-1][x];
		}
	}

	FORE(j,1,19){
		FOR(i,n){
			int x = parent[j-1][i];
			if(x != -1)dist2[j][i] = min(dist2[j-1][i],dist2[j-1][x]);
			else dist2[j][i] = dist2[j-1][i];
		}
	}

}

inline bool isEscapePoss(int np,int node){
	bool isOut1 = st[np]>st[node] or en[np]<st[node];
	bool isOut2 = st[np]>st[e] or en[np]<st[e];
	return !(isOut1^isOut2);
}

ll getMin(int node,int p){
	ll mn = INF;
	/*while(p != node){
		cout << node << " " << dist2[0][node] << endl;
		mn = min(mn,dist2[0][node]);
		node = parent[0][node];
		if(node == -1)break;
	}
	cout << endl;
	return mn;*/
	for(int j = 18;j>=0;j--){
		if(node == -1)continue;
		if(parent[j][node] == -1)continue;
		if(dpt[parent[j][node]] <= dpt[p])continue;
		mn = min(mn,dist2[j][node]);
		node = parent[j][node];
	}
//	cout << node << "::" << dist2[0][node]<< endl;
	mn = min(mn,dist2[0][node]);
	return mn;
}


#define endl '\n'
int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int q;
	cin >> n >> s >> q >> e;
	e--;
	FOR(i,n-1){
		int a,b,c;
		cin >> a >> b >> c;
		a--;b--;
		edges.pb({{a,b},c});
		g[a].pb({b,c});
		g[b].pb({a,c});
	}
	FOR(i,20)FOR(j,n)dist2[i][j] = 10*INF;
	FOR(i,s){
		int x;cin >> x;x--;special.pb(x);
		sp[x] = 1;
	}
	// proprocess the tree.
	dfs1(e);
	dfs2(e);
	FOR(i,n)dist2[0][i] -= 2*dist[i];
	//FOR(i,n)cout << dist[i] << " ";cout << endl;
	computeSparseTable();
	
	FOR(i,q){
		int a,b;
		cin >> a >> b;
		a--;b--;
		int x = (dist[edges[a].ff.ff] > dist[edges[a].ff.ss])?edges[a].ff.ff : edges[a].ff.ss;
		int y = (dist[edges[a].ff.ff] <= dist[edges[a].ff.ss])?edges[a].ff.ff : edges[a].ff.ss;
		if(isEscapePoss(x,b)){
			cout << "escaped" << endl;
		}else{
			ll dt = min(getMin(b,y),dist2[0][x]) + dist[b];
			if(dt >= INF){
				cout << "oo" << endl;
			}else{
				cout << dt << endl;
			}
		}
	}
	return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 3064 KB Output is correct
2 Correct 8 ms 3064 KB Output is correct
3 Correct 7 ms 3064 KB Output is correct
4 Correct 7 ms 3064 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 3064 KB Output is correct
2 Correct 8 ms 3064 KB Output is correct
3 Correct 7 ms 3064 KB Output is correct
4 Correct 7 ms 3064 KB Output is correct
5 Correct 6 ms 3320 KB Output is correct
6 Correct 5 ms 3324 KB Output is correct
7 Correct 6 ms 3324 KB Output is correct
8 Correct 5 ms 3320 KB Output is correct
9 Correct 5 ms 3320 KB Output is correct
10 Correct 6 ms 3320 KB Output is correct
11 Correct 6 ms 3320 KB Output is correct
12 Correct 5 ms 3320 KB Output is correct
13 Correct 6 ms 3320 KB Output is correct
14 Correct 5 ms 3320 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 203 ms 40456 KB Output is correct
2 Correct 210 ms 40164 KB Output is correct
3 Correct 239 ms 40532 KB Output is correct
4 Correct 249 ms 41860 KB Output is correct
5 Correct 236 ms 42084 KB Output is correct
6 Correct 313 ms 43844 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 3064 KB Output is correct
2 Correct 8 ms 3064 KB Output is correct
3 Correct 7 ms 3064 KB Output is correct
4 Correct 7 ms 3064 KB Output is correct
5 Correct 6 ms 3320 KB Output is correct
6 Correct 5 ms 3324 KB Output is correct
7 Correct 6 ms 3324 KB Output is correct
8 Correct 5 ms 3320 KB Output is correct
9 Correct 5 ms 3320 KB Output is correct
10 Correct 6 ms 3320 KB Output is correct
11 Correct 6 ms 3320 KB Output is correct
12 Correct 5 ms 3320 KB Output is correct
13 Correct 6 ms 3320 KB Output is correct
14 Correct 5 ms 3320 KB Output is correct
15 Correct 203 ms 40456 KB Output is correct
16 Correct 210 ms 40164 KB Output is correct
17 Correct 239 ms 40532 KB Output is correct
18 Correct 249 ms 41860 KB Output is correct
19 Correct 236 ms 42084 KB Output is correct
20 Correct 313 ms 43844 KB Output is correct
21 Correct 177 ms 38920 KB Output is correct
22 Correct 191 ms 38776 KB Output is correct
23 Correct 212 ms 38888 KB Output is correct
24 Correct 257 ms 40604 KB Output is correct
25 Correct 231 ms 43108 KB Output is correct
26 Correct 180 ms 39012 KB Output is correct
27 Correct 198 ms 38756 KB Output is correct
28 Correct 214 ms 38884 KB Output is correct
29 Correct 245 ms 40164 KB Output is correct
30 Correct 347 ms 41572 KB Output is correct
31 Correct 181 ms 37832 KB Output is correct
32 Correct 188 ms 35584 KB Output is correct
33 Correct 223 ms 35964 KB Output is correct
34 Correct 248 ms 37476 KB Output is correct
35 Correct 252 ms 39780 KB Output is correct
36 Correct 213 ms 37996 KB Output is correct