oj.uz

Submission #60376

# Submission time Handle Problem Language Result Execution time Memory
60376 2018-07-24T03:33:18 Z admin Railway Trip (JOI17_railway_trip) C++14
100 / 100
 598 ms 177052 KB 
#include <cstdio>
#include <algorithm>
#include <vector>
 
static const int MAXN = 100000;
static const int DEPTH = 20;
 
using namespace std;
 
struct segtree
{
	static const int kDepth = 17;
	static const int kSize = 1 << kDepth;
	pair<int, int> *data;
 
	segtree() {
		data = new pair<int, int>[2 * kSize];
	}
	void init(int len, int* v)
	{
		for (int i = 0; i < len; ++i) data[kSize + i] = make_pair(v[i], -i);
		for (int i = len; i < kSize; ++i) data[kSize + i] = make_pair(-1, -i);
		for (int i = kSize - 1; i >= 1; --i) data[i] = max(data[i * 2], data[i * 2 + 1]);
	}
	pair<int, int> query(int l, int r)
	{
		l += kSize;
		r += kSize;
		pair<int, int> ret(-1, -1);
		while (l < r) {
			if (l & 1) ret = max(ret, data[l++]);
			if (r & 1) ret = max(ret, data[--r]);
			l >>= 1; r >>= 1;
		}
		ret.second = -ret.second;
		return ret;
	}
};
 
int N, K, Q;
int L[MAXN];
vector<int> child[MAXN * 2]; int dep[MAXN * 2], ci[MAXN * 2];
int nlast, root;
int wnode[MAXN];
segtree lst;
bool nonstop;
 
int parent[MAXN * 6][DEPTH], weight[MAXN * 6][DEPTH];
 
int build(int l, int r)
{
	if (r - l == 1) {
		return wnode[l] = nlast++;
	}
	auto tmp = lst.query(l + 1, r);
	int bp = tmp.first;
	vector<int> sep;
	sep.push_back(l);
	sep.push_back(tmp.second);
	for (;;) {
		auto q = lst.query(sep.back() + 1, r);
		if (q.first != bp) break;
		sep.push_back(q.second);
	}
	sep.push_back(r);
 
	int ret = nlast++;
	for (int i = 0; i < (int)sep.size() - 1; ++i) {
		child[ret].push_back(build(sep[i], sep[i + 1]));
	}
	return ret;
}
inline int forest_vtx(int p, int mode)
{
	// mode 0: (x+1, x), 1: (x, x), 2: (x, x+1)
	return p * 3 + mode;
}
void assign_parent(int p, int par, int tl, int tr)
{
	tl = min(tl, tr + 1);
	tr = min(tr, tl + 1);
	if (tl == tr + 1) {
		parent[p][0] = forest_vtx(par, 0);
		weight[p][0] = tr;
	} else if (tl == tr) {
		parent[p][0] = forest_vtx(par, 1);
		weight[p][0] = tr;
	} else {
		parent[p][0] = forest_vtx(par, 2);
		weight[p][0] = tl;
	}
}
void gen_forest(int p)
{
	for (int p2 = p * 3; p2 < (p + 1) * 3; ++p2) {
		for (int i = 1; i < DEPTH; ++i) {
			if (parent[p2][i - 1] == -1) {
				parent[p2][i] = -1;
				weight[p2][i] = weight[p2][i - 1];
			} else {
				parent[p2][i] = parent[parent[p2][i - 1]][i - 1];
				weight[p2][i] = weight[p2][i - 1] + weight[parent[p2][i - 1]][i - 1];
			}
		}
	}
	for (int i = 0; i < child[p].size(); ++i) {
		int q = child[p][i];
		int j = (int)child[p].size() - i - 1;
		dep[q] = dep[p] + 1;
		ci[q] = i;
		assign_parent(forest_vtx(q, 0), p, 1 + i, j);
		assign_parent(forest_vtx(q, 1), p, i, j);
		assign_parent(forest_vtx(q, 2), p, i, j + 1);
		gen_forest(q);
	}
}
pair<int, int> descend(int p, int d)
{
	int dist = 0;
	for (int i = DEPTH - 1; i >= 0; --i) if (d & (1 << i)) {
		dist += weight[p][i];
		p = parent[p][i];
	}
	return{ p, dist };
}
int solve(int a, int b)
{
	if (b == a + 1) return 1;
	int p = forest_vtx(wnode[a], 2);
	int q = forest_vtx(wnode[b - 1], 0);
	int dist = 0;
	if (dep[p / 3] < dep[q / 3]) {
		auto tmp = descend(q, dep[q / 3] - dep[p / 3]);
		dist = tmp.second;
		q = tmp.first;
	} else if (dep[p / 3] > dep[q / 3]) {
		auto tmp = descend(p, dep[p / 3] - dep[q / 3]);
		dist = tmp.second;
		p = tmp.first;
	}
	for (int i = DEPTH - 1; i >= 0; --i) {
		if (parent[p][i] / 3 != parent[q][i] / 3) {
			dist += weight[p][i] + weight[q][i];
			p = parent[p][i];
			q = parent[q][i];
		}
	}
	int ret = N;
	ret = min(ret, dist + ci[q / 3] - ci[p / 3] - 1 + (p % 3 == 2 ? 1 : 0) + (q % 3 == 0 ? 1 : 0));
	if (parent[p][0] / 3 != root || nonstop) {
		ret = min(ret, dist + ci[p / 3] + ((int)child[parent[p][0] / 3].size() - ci[q / 3] - 1) + (p % 3 == 0 ? 1 : 0) + (q % 3 == 2 ? 1 : 0) + 1);
	}
	return ret;
}
int main()
{
	scanf("%d%d%d", &N, &K, &Q);
	nonstop = true;
	for (int i = 0; i < N; ++i) {
		scanf("%d", L + i);
		--L[i];
		if (i != 0 && i != N - 1 && L[i] == K - 1) nonstop = false;
	}
	
	nlast = 0;
	lst.init(N, L);
	root = build(0, N - 1);
	dep[root] = 0; ci[root] = 0;
	for (int i = 0; i < 3; ++i) {
		parent[root * 3 + i][0] = -1;
		weight[root * 3 + i][0] = 0;
	}
	gen_forest(root);
 
	for (int q = 0; q < Q; ++q) {
		int a, b;
		scanf("%d%d", &a, &b);
		--a; --b;
		if (a > b) swap(a, b);
		printf("%d\n", solve(a, b) - 1);
	}
	return 0;
}

Compilation message

railway_trip.cpp: In function 'int main()':
railway_trip.cpp:157:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d", &N, &K, &Q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
railway_trip.cpp:160:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", L + i);
   ~~~~~^~~~~~~~~~~~~
railway_trip.cpp:177:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a, &b);
   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 7416 KB Output is correct
2 Correct 12 ms 7492 KB Output is correct
3 Correct 11 ms 7552 KB Output is correct
4 Correct 12 ms 7608 KB Output is correct
5 Correct 11 ms 7608 KB Output is correct
6 Correct 6 ms 7608 KB Output is correct
7 Correct 12 ms 7608 KB Output is correct
8 Correct 13 ms 7640 KB Output is correct
9 Correct 12 ms 7640 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 8516 KB Output is correct
2 Correct 168 ms 92272 KB Output is correct
3 Correct 176 ms 98480 KB Output is correct
4 Correct 197 ms 103156 KB Output is correct
5 Correct 209 ms 105384 KB Output is correct
6 Correct 227 ms 108172 KB Output is correct
7 Correct 242 ms 109080 KB Output is correct
8 Correct 80 ms 109080 KB Output is correct
9 Correct 216 ms 109080 KB Output is correct
10 Correct 139 ms 109080 KB Output is correct
11 Correct 197 ms 109080 KB Output is correct
12 Correct 195 ms 109080 KB Output is correct
13 Correct 199 ms 109080 KB Output is correct
14 Correct 191 ms 109080 KB Output is correct
15 Correct 200 ms 109080 KB Output is correct
16 Correct 215 ms 109080 KB Output is correct
17 Correct 195 ms 114296 KB Output is correct
18 Correct 205 ms 114896 KB Output is correct
19 Correct 207 ms 115596 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 365 ms 115596 KB Output is correct
2 Correct 347 ms 115596 KB Output is correct
3 Correct 325 ms 115596 KB Output is correct
4 Correct 289 ms 115596 KB Output is correct
5 Correct 342 ms 115596 KB Output is correct
6 Correct 305 ms 115596 KB Output is correct
7 Correct 388 ms 116548 KB Output is correct
8 Correct 240 ms 116548 KB Output is correct
9 Correct 184 ms 116548 KB Output is correct
10 Correct 220 ms 116548 KB Output is correct
11 Correct 193 ms 116548 KB Output is correct
12 Correct 186 ms 116548 KB Output is correct
13 Correct 206 ms 116548 KB Output is correct
14 Correct 278 ms 116548 KB Output is correct
15 Correct 264 ms 116548 KB Output is correct
16 Correct 266 ms 116548 KB Output is correct

Subtask #4
55.0 / 55.0

# Verdict Execution time Memory Grader output
1 Correct 316 ms 139436 KB Output is correct
2 Correct 325 ms 141328 KB Output is correct
3 Correct 378 ms 142788 KB Output is correct
4 Correct 351 ms 144736 KB Output is correct
5 Correct 182 ms 144736 KB Output is correct
6 Correct 454 ms 144736 KB Output is correct
7 Correct 501 ms 144736 KB Output is correct
8 Correct 348 ms 144736 KB Output is correct
9 Correct 370 ms 144736 KB Output is correct
10 Correct 355 ms 144736 KB Output is correct
11 Correct 457 ms 144736 KB Output is correct
12 Correct 447 ms 144736 KB Output is correct
13 Correct 418 ms 144736 KB Output is correct
14 Correct 558 ms 151512 KB Output is correct
15 Correct 468 ms 160564 KB Output is correct
16 Correct 598 ms 174132 KB Output is correct
17 Correct 451 ms 174132 KB Output is correct
18 Correct 415 ms 174132 KB Output is correct
19 Correct 431 ms 174132 KB Output is correct
20 Correct 373 ms 174132 KB Output is correct
21 Correct 349 ms 174132 KB Output is correct
22 Correct 429 ms 175248 KB Output is correct
23 Correct 414 ms 177052 KB Output is correct