oj.uz

Submission #435852

# Submission time Handle Problem Language Result Execution time Memory
435852 2021-06-23T19:39:22 Z jerzyk Valley (BOI19_valley) C++14
100 / 100
 483 ms 59844 KB 
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
const int N = 100 * 1000 + 7;
const ll I = 1000000LL * 1000000LL * 1000000LL; 
int lca[20][N], poz[N], czy[N], od[N];
ll dol[3][N], gor[N], nws[20][N], rnws[20][N], odl[N];
vector<pair<int, ll>> kr[N];
pair<int, int> ed[N];

void DFS(int v)
{
	od[v] = 1;
	int i;
	ll aw;
	dol[0][v] = I;
	dol[1][v] = I;
	dol[2][v] = I;
	if(czy[v] == 1)
		dol[0][v] = 0;
	gor[v] = I;
	for(i = 0; i < (int)kr[v].size(); ++i)
	{
		if(od[kr[v][i].first] == 1)
			continue;
		if(dol[0][v] == dol[0][kr[v][i].first] + kr[v][i].second)
			rnws[0][kr[v][i].first] = dol[1][v];
		else
			rnws[0][kr[v][i].first] = dol[0][v];
		poz[kr[v][i].first] = poz[v] + 1;
		odl[kr[v][i].first] = odl[v] + kr[v][i].second;
		lca[0][kr[v][i].first] = v;
		DFS(kr[v][i].first);
		aw = dol[0][kr[v][i].first] + kr[v][i].second;
		if(aw < dol[0][v])
			swap(aw, dol[0][v]);
		if(aw < dol[1][v])
			swap(aw, dol[1][v]);
		if(aw < dol[2][v])
			swap(aw, dol[2][v]);
	}
}

void DFS2(int v, int o)
{
	od[v] = 1;
	int i;
	if(czy[v] == 1)
		gor[v] = 0LL;
	nws[0][v] = dol[0][v];
	for(i = 0; i < (int)kr[v].size(); ++i)
	{
		if(od[kr[v][i].first] == 1)
			continue;
		gor[kr[v][i].first] = gor[v];
		if(dol[0][kr[v][i].first] + kr[v][i].second == dol[0][v])
			gor[kr[v][i].first] = min(gor[kr[v][i].first], dol[1][v] + kr[v][i].second);
		else
			gor[kr[v][i].first] = min(gor[kr[v][i].first], dol[0][v] + kr[v][i].second);
		DFS2(kr[v][i].first, o);
	}
}

void WyLCA(int n)
{
	int i, j;
	for(j = 1; j <= 18; ++j)
	{
		for(i = 1; i <= n; ++i)
		{
			lca[j][i] = lca[j - 1][lca[j - 1][i]];
			nws[j][i] = min(nws[j - 1][i], nws[j - 1][lca[j - 1][i]] + odl[i] - odl[lca[j - 1][i]]);
			rnws[j][i] = min(rnws[j - 1][lca[j - 1][i]], rnws[j - 1][i] + odl[lca[j - 1][i]] - lca[j][i]);
		}
	}
}

pair<int, ll> LCA(int a, int b)
{
	int i, pa, pb;
	if(a == b)
		return make_pair(a, dol[0][a]);
	pa = a;
	pb = b;
	ll w1, w2;
	w1 = I;
	w2 = I;
	if(poz[a] > poz[b])
	{
		for(i = 18; i >= 0; --i)
		{
			if(poz[lca[i][a]] > poz[b])
			{
				w1 = min(w1, nws[i][a] + odl[pa] - odl[a]);
				a = lca[i][a];
			}
		}
		if(lca[0][a] == b)
		{
			w1 = min(w1, odl[pa] - odl[b] + dol[0][b]);
		}
		w1 = min(w1, nws[0][a] + odl[pa] - odl[a]);
		a = lca[0][a];
		//cout << a << " " << b << "\n";
	}
	if(poz[b] > poz[a])
	{
		for(i = 18; i >= 0; --i)
		{
			if(poz[lca[i][b]] > poz[a])
			{
				w2 = min(w2 + odl[b] - odl[lca[i][b]], rnws[i][b]);
				b = lca[i][b];
			}
		}
		w2 = min(w2 + odl[b] - odl[lca[0][b]], rnws[0][b]);
		b = lca[0][b];
	}
	if(b == pa)
	{
		return make_pair(b, min(min(w1, w2), gor[a]));
	}
	if(a == pb)
	{
		return make_pair(a, min(w1, w2));
	}
	for(i = 18; i >= 0; --i)
	{
		if(lca[i][a] != lca[i][b])
		{
			w2 = min(w2 + odl[b] - odl[lca[i][b]], rnws[i][b]);
			b = lca[i][b];
			w1 = min(w1, nws[i][a] + odl[pa] - odl[a]);
			a = lca[i][a];
		}
	}
	w2 = min(w2 + odl[b] - odl[lca[0][b]], rnws[0][b]);
	b = lca[0][b];
	w1 = min(w1, nws[0][a] + odl[pa] - odl[a]);
	a = lca[0][a];
	w2 += (odl[pa] - odl[a]);
	w1 = min(w1, gor[a]);
	return make_pair(a, min(w1, w2));
}

void Wyw(int s, int n)
{
	int i, j;
	for(i = 1; i <= n; ++i)
	{
		for(j = 0; j <= 18; ++j)
		{
			nws[j][i] = I;
			rnws[j][i] = I;
		}
	}
	poz[s] = 0;
	odl[s] = 0LL;
	lca[0][s] = s;
	DFS(s);
	for(i = 1; i <= n; ++i)
		od[i] = 0;
	DFS2(s, s);
}

void Odp(int q)
{
	int i, v, x, a, b;
	pair<int, ll> w;
	for(i = 1; i <= q; ++i)
	{
		cin >> x >> v;
		a = ed[x].first;
		b = ed[x].second;
		if(poz[a] < poz[b])
			w = LCA(v, b);
		else
			w = LCA(v, a);
		//cout << w.first << " " << LCA(v, b).first << "\n";
		if(poz[w.first] <= min(poz[a], poz[b]))
		{
			cout << "escaped\n";
		}
		else
		{
			if(w.second >= I)
				cout << "oo\n";
			else
				cout << w.second << "\n";
		}
	}
}

void Wczytaj(int &n, int &s, int &q)
{
	int i, k, a;
	ll d;
	cin >> n >> k >> q >> s;
	for(i = 1; i < n; ++i)
	{
		cin >> ed[i].first >> ed[i].second >> d;
		kr[ed[i].first].push_back(make_pair(ed[i].second, d));
		kr[ed[i].second].push_back(make_pair(ed[i].first, d));
	}
	for(i = 1; i <= k; ++i)
	{
		cin >> a;
		czy[a] = 1;
	}
}

void Valley()
{
	int n, s, q;
	Wczytaj(n, s, q);
	Wyw(s, n);
	WyLCA(n);
	Odp(q);
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	Valley();

	return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3148 KB Output is correct
2 Correct 6 ms 3204 KB Output is correct
3 Correct 6 ms 3148 KB Output is correct
4 Correct 6 ms 3148 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3148 KB Output is correct
2 Correct 6 ms 3204 KB Output is correct
3 Correct 6 ms 3148 KB Output is correct
4 Correct 6 ms 3148 KB Output is correct
5 Correct 3 ms 3532 KB Output is correct
6 Correct 3 ms 3460 KB Output is correct
7 Correct 4 ms 3456 KB Output is correct
8 Correct 3 ms 3528 KB Output is correct
9 Correct 3 ms 3404 KB Output is correct
10 Correct 4 ms 3532 KB Output is correct
11 Correct 3 ms 3532 KB Output is correct
12 Correct 3 ms 3532 KB Output is correct
13 Correct 5 ms 3532 KB Output is correct
14 Correct 5 ms 3532 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 238 ms 55364 KB Output is correct
2 Correct 250 ms 55116 KB Output is correct
3 Correct 328 ms 55424 KB Output is correct
4 Correct 451 ms 57276 KB Output is correct
5 Correct 425 ms 57368 KB Output is correct
6 Correct 483 ms 59540 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 3148 KB Output is correct
2 Correct 6 ms 3204 KB Output is correct
3 Correct 6 ms 3148 KB Output is correct
4 Correct 6 ms 3148 KB Output is correct
5 Correct 3 ms 3532 KB Output is correct
6 Correct 3 ms 3460 KB Output is correct
7 Correct 4 ms 3456 KB Output is correct
8 Correct 3 ms 3528 KB Output is correct
9 Correct 3 ms 3404 KB Output is correct
10 Correct 4 ms 3532 KB Output is correct
11 Correct 3 ms 3532 KB Output is correct
12 Correct 3 ms 3532 KB Output is correct
13 Correct 5 ms 3532 KB Output is correct
14 Correct 5 ms 3532 KB Output is correct
15 Correct 238 ms 55364 KB Output is correct
16 Correct 250 ms 55116 KB Output is correct
17 Correct 328 ms 55424 KB Output is correct
18 Correct 451 ms 57276 KB Output is correct
19 Correct 425 ms 57368 KB Output is correct
20 Correct 483 ms 59540 KB Output is correct
21 Correct 239 ms 54416 KB Output is correct
22 Correct 296 ms 54292 KB Output is correct
23 Correct 278 ms 54488 KB Output is correct
24 Correct 340 ms 56540 KB Output is correct
25 Correct 479 ms 59484 KB Output is correct
26 Correct 228 ms 54664 KB Output is correct
27 Correct 349 ms 54448 KB Output is correct
28 Correct 281 ms 54704 KB Output is correct
29 Correct 369 ms 56164 KB Output is correct
30 Correct 402 ms 57760 KB Output is correct
31 Correct 229 ms 54864 KB Output is correct
32 Correct 271 ms 54720 KB Output is correct
33 Correct 309 ms 55148 KB Output is correct
34 Correct 426 ms 56884 KB Output is correct
35 Correct 450 ms 59844 KB Output is correct
36 Correct 378 ms 56832 KB Output is correct