oj.uz

Submission #208788

# Submission time Handle Problem Language Result Execution time Memory
208788 2020-03-12T07:51:29 Z E869120 Demarcation (BOI14_demarcation) C++14
50 / 100
 500 ms 43896 KB 
#include <iostream>
#include <vector>
#include <set>
#include <limits>
#include <cmath>
#include <tuple>
#include <algorithm>
using namespace std;
#pragma warning (disable: 4996)

// -------------------------------------- セグメントツリー ----------------------------------
class BIT {
public:
	int size_ = 1;
	vector<int> bit;

	void init(int sz) {
		size_ = sz + 2;
		bit.resize(size_ + 2, 0);
	}
	void add(int pos, int x) {
		pos++;
		while (pos <= size_) {
			bit[pos] += x;
			pos += (pos & -pos);
		}
	}
	int sum(int pos) {
		pos++; int s = 0;
		while (pos >= 1) {
			s += bit[pos];
			pos -= (pos & -pos);
		}
		return s;
	}
};

// ------------------------------------- ハッシュ関連の関数 ---------------------------------
long long BASE = 11111111111111LL;
long long power[1 << 18];
long long hush[1 << 18];

void init() {
	power[0] = 1;
	for (int i = 1; i <= 250000; i++) power[i] = BASE * power[i - 1];
}

// -------------------------------------- 幾何関連の関数 ------------------------------------
struct Point {
	long long px, py;
};

long long dst(Point a1, Point a2) {
	return abs(a1.px - a2.px) + abs(a1.py - a2.py);
}

vector<Point> fixes(vector<Point> G) {
	vector<Point> G2;
	for (int i = 0; i < G.size(); i++) {
		int pre = (i + G.size() - 1) % G.size(), nex = (i + 1) % G.size();
		bool s1 = false; if (G[pre].px == G[i].px) s1 = true;
		bool s2 = false; if (G[i].px == G[nex].px) s2 = true;
		if (s1 != s2) G2.push_back(G[i]);
	}
	return G2;
}

long long getmin(vector<long long> t) {
	hush[0] = 1;
	for (int i = 1; i <= t.size() * 2; i++) hush[i] = BASE * hush[i - 1] + t[(i - 1) % t.size()];

	long long minv = 9223372036854775807LL;
	for (int i = 0; i < t.size(); i++) {
		long long val = hush[t.size() + i] - hush[i] * power[t.size()];
		minv = min(minv, val);
	}
	return minv;
}

long long hashval(vector<Point> v) {
	vector<long long> t;
	for (int i = 0; i < v.size(); i++) {
		t.push_back(dst(v[i], v[(i + 1) % v.size()]));
	}
	long long p1 = getmin(t); reverse(t.begin(), t.end());
	long long p2 = getmin(t);
	return min(p1, p2);
}

bool identical(vector<Point> v1, vector<Point> v2) {
	v1 = fixes(v1);
	v2 = fixes(v2);
	if (v1.size() != v2.size()) return false;
	long long val1 = hashval(v1);
	long long val2 = hashval(v2);
	if (val1 == val2) return true;
	return false;
}

// ---------------------------------- 本質 ------------------------------------
long long N, L[1 << 18];
Point Z[1 << 18];

bool dir[1 << 18];
vector<pair<long long, int>> V[1 << 18][2];

vector<tuple<long long, int, int>> T[1 << 18][2];
set<tuple<long long, int, int>> Set;

// ---------------------------- その他のライブラリ ---------------------------
bool Rotate(int p1, int p2) {
	if (p1 > p2) p2 += N;
	if (p2 - p1 == 1) return true;
	return false;
}

long long getlen(int p1, int p2) {
	// p1 -> p2 の距離
	if (p1 > p2) p2 += N;
	return L[p2] - L[p1];
}

void adds(vector<Point>& a1, int cl, int cr) {
	if (cl > cr) cr += N;
	for (int i = cl; i <= cr; i++) {
		if (a1[a1.size() - 1].px == Z[i % N].px && a1[a1.size() - 1].py == Z[i % N].py) continue;
		a1.push_back(Z[i % N]);
	}
}

vector<Point> solve() {
	// ステップ A. 座標圧縮をする
	vector<long long> X, Y;
	for (int i = 0; i < N; i++) X.push_back(Z[i].px);
	for (int i = 0; i < N; i++) Y.push_back(Z[i].py);
	sort(X.begin(), X.end()); X.erase(unique(X.begin(), X.end()), X.end());
	sort(Y.begin(), Y.end()); Y.erase(unique(Y.begin(), Y.end()), Y.end());

	// ステップ B. 初期化をする
	for (int i = 0; i <= N; i++) {
		V[i][0].clear();
		V[i][1].clear();
	}
	for (int i = 0; i <= N * 2; i++) {
		T[i][0].clear();
		T[i][1].clear();
	}

	// ステップ C. BIT で向きを求める（false: 左側、true: 右側）
	for (int i = 0; i < N; i++) {
		if (Z[i].px == Z[(i + 1) % N].px) continue;
		int pos1 = lower_bound(X.begin(), X.end(), Z[(i + 0) % N].px) - X.begin();
		int pos2 = lower_bound(X.begin(), X.end(), Z[(i + 1) % N].px) - X.begin();
		if (pos1 > pos2) swap(pos1, pos2);
		V[pos1][0].push_back(make_pair(Z[(i + 0) % N].py, i));
		V[pos2][1].push_back(make_pair(Z[(i + 0) % N].py, i));
	}
	BIT ZZ; ZZ.init(Y.size() + 2);
	for (int i = 0; i < X.size(); i++) {
		sort(V[i][0].begin(), V[i][0].end());
		for (pair<long long, int> j : V[i][1]) {
			int pos1 = lower_bound(Y.begin(), Y.end(), j.first) - Y.begin();
			ZZ.add(pos1, -1);
		}
		for (pair<long long, int> j : V[i][0]) {
			int pos1 = lower_bound(Y.begin(), Y.end(), j.first) - Y.begin();
			ZZ.add(pos1, 1);
			if (ZZ.sum(pos1) % 2 == 0) dir[j.second] = true;
			else dir[j.second] = false;
		}
	}

	// ステップ D. 境界値も含め、どこで push するか vector (T) に突っ込む
	for (int i = 0; i < N; i++) {
		if (Z[i].px == Z[(i + 1) % N].px) continue;
		int pos1 = lower_bound(X.begin(), X.end(), Z[(i + 0) % N].px) - X.begin();
		int pos2 = lower_bound(X.begin(), X.end(), Z[(i + 1) % N].px) - X.begin();
		int s0 = (i + N - 1) % N, s1 = (i + 0) % N, s2 = (i + 1) % N, s3 = (i + 2) % N;
		if (pos1 > pos2) { swap(pos1, pos2); swap(s1, s2); swap(s0, s3); }

		if (dir[i] == false) {
			int cl = pos1 * 2, cr = pos2 * 2;
			if (Z[s0].py > Z[s1].py) cl++;
			if (Z[s2].py > Z[s3].py) cr++;
			T[cl][0].push_back(make_tuple(Z[i].py, s1, s2));
			T[cr][1].push_back(make_tuple(Z[i].py, s1, s2));
		}
		else {
			int cl = pos1 * 2, cr = pos2 * 2;
			if (Z[s0].py < Z[s1].py) cl++;
			if (Z[s2].py < Z[s3].py) cr++;
			T[cl][0].push_back(make_tuple(Z[i].py, s1, s2));
			T[cr][1].push_back(make_tuple(Z[i].py, s1, s2));
		}
	}

	// ステップ E. 平面走査をする
	for (int i = 0; i <= (X.size() - 1) * 2; i++) {
		for (tuple<long long, int, int> j : T[i][1]) Set.erase(j);
		for (tuple<long long, int, int> j : T[i][0]) Set.insert(j);

		long long vl, vr;
		if (i % 2 == 0) { vl = X[i / 2]; vr = X[i / 2]; }
		if (i % 2 == 1) { vl = X[i / 2] + 1; vr = X[(i + 1) / 2] - 1; }

		auto itr = Set.begin();
		while (itr != Set.end()) {
			tuple<long long, int, int> fl = (*itr); itr++;
			tuple<long long, int, int> fr = (*itr); itr++;
			long long L1 = 0;
			if (Rotate(get<1>(fl), get<2>(fl)) == true) L1 = getlen(get<1>(fr), get<1>(fl));
			if (Rotate(get<1>(fl), get<2>(fl)) == false) L1 = getlen(get<1>(fl), get<1>(fr));
			long long sl = L1 + abs(Z[get<1>(fl)].px - vl) + abs(Z[get<1>(fr)].px - vl);
			long long sr = L1 + abs(Z[get<1>(fl)].px - vr) + abs(Z[get<1>(fr)].px - vr);
			if (sl <= L[N] / 2LL && L[N] / 2LL <= sr && ((L[N] / 2LL) - sl) % 2LL == 0LL) {
				long long zahyou = vl + ((L[N] / 2LL) - sl) / 2LL;
				vector<Point> D1, D2;
				if (Rotate(get<1>(fl), get<2>(fl)) == true) {
					long long yl_val = get<0>(fl);
					long long yr_val = get<0>(fr);
					D1.push_back(Point{ zahyou, yr_val });
					adds(D1, get<1>(fr), get<1>(fl));
					if (D1[D1.size() - 1].px != zahyou || D1[D1.size() - 1].py != yl_val) D1.push_back({ zahyou, yl_val });
					D2.push_back(Point{ zahyou, yl_val });
					adds(D2, get<2>(fl), get<2>(fr));
					if (D2[D2.size() - 1].px != zahyou || D2[D2.size() - 1].py != yr_val) D2.push_back({ zahyou, yr_val });
				}
				if (Rotate(get<1>(fl), get<2>(fl)) == false) {
					long long yl_val = get<0>(fl);
					long long yr_val = get<0>(fr);
					D1.push_back(Point{ zahyou, yl_val });
					adds(D1, get<1>(fl), get<1>(fr));
					if (D1[D1.size() - 1].px != zahyou || D1[D1.size() - 1].py != yr_val) D1.push_back({ zahyou, yr_val });
					D2.push_back(Point{ zahyou, yr_val });
					adds(D2, get<2>(fr), get<2>(fl));
					if (D2[D2.size() - 1].px != zahyou || D2[D2.size() - 1].py != yl_val) D2.push_back({ zahyou, yl_val });
				}
				bool flag = identical(D1, D2);
				if (flag == true) {
					return vector<Point>{Point{ zahyou, get<0>(fl) }, Point{ zahyou, get<0>(fr) }};
				}
			}
		}
	}

	return vector<Point>{};
}

int main() {
	// ステップ 1. 入力・前準備
	scanf("%lld", &N); init();
	for (int i = 0; i < N; i++) scanf("%lld%lld", &Z[i].px, &Z[i].py);
	for (int i = 0; i < N * 2; i++) L[i + 1] = dst(Z[i % N], Z[(i + 1) % N]);
	for (int i = 1; i <= N * 2; i++) L[i] += L[i - 1];

	// ステップ 2. x 側を探索
	vector<Point> E1 = solve();
	if (E1.size() >= 1) {
		cout << E1[0].px << " " << E1[0].py << " " << E1[1].px << " " << E1[1].py << endl;
		return 0;
	}

	// ステップ 3. y 側を探索
	for (int i = 0; i < N; i++) swap(Z[i].px, Z[i].py);
	vector<Point> E2 = solve();
	if (E2.size() >= 1) {
		cout << E2[0].py << " " << E2[0].px << " " << E2[1].py << " " << E2[1].px << endl;
		return 0;
	}

	cout << "NO" << endl;
	return 0;
}

Compilation message

demarcation.cpp:9:0: warning: ignoring #pragma warning  [-Wunknown-pragmas]
 #pragma warning (disable: 4996)
 
demarcation.cpp: In function 'std::vector<Point> fixes(std::vector<Point>)':
demarcation.cpp:59:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < G.size(); i++) {
                  ~~^~~~~~~~~~
demarcation.cpp: In function 'long long int getmin(std::vector<long long int>)':
demarcation.cpp:70:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 1; i <= t.size() * 2; i++) hush[i] = BASE * hush[i - 1] + t[(i - 1) % t.size()];
                  ~~^~~~~~~~~~~~~~~
demarcation.cpp:73:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < t.size(); i++) {
                  ~~^~~~~~~~~~
demarcation.cpp: In function 'long long int hashval(std::vector<Point>)':
demarcation.cpp:82:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < v.size(); i++) {
                  ~~^~~~~~~~~~
demarcation.cpp: In function 'std::vector<Point> solve()':
demarcation.cpp:159:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < X.size(); i++) {
                  ~~^~~~~~~~~~
demarcation.cpp:198:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i <= (X.size() - 1) * 2; i++) {
                  ~~^~~~~~~~~~~~~~~~~~~~~
demarcation.cpp: In function 'int main()':
demarcation.cpp:251:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &N); init();
  ~~~~~^~~~~~~~~~~~
demarcation.cpp:252:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 0; i < N; i++) scanf("%lld%lld", &Z[i].px, &Z[i].py);
                              ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
demarcation.cpp: In function 'std::vector<Point> solve()':
demarcation.cpp:214:56: warning: 'vr' may be used uninitialized in this function [-Wmaybe-uninitialized]
    long long sr = L1 + abs(Z[get<1>(fl)].px - vr) + abs(Z[get<1>(fr)].px - vr);
                                                     ~~~^~~~~~~~~~~~~~~~~~~~~~~
demarcation.cpp:213:56: warning: 'vl' may be used uninitialized in this function [-Wmaybe-uninitialized]
    long long sl = L1 + abs(Z[get<1>(fl)].px - vl) + abs(Z[get<1>(fr)].px - vl);
                                                     ~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 28940 KB Output is correct
2 Correct 21 ms 27004 KB Output is correct
3 Correct 21 ms 26872 KB Output is correct
4 Correct 34 ms 29012 KB Output is correct
5 Correct 22 ms 26872 KB Output is correct
6 Correct 21 ms 26872 KB Output is correct
7 Correct 21 ms 26872 KB Output is correct
8 Correct 21 ms 26872 KB Output is correct
9 Correct 118 ms 43888 KB Output is correct
10 Correct 21 ms 27000 KB Output is correct
11 Correct 22 ms 27000 KB Output is correct
12 Correct 21 ms 26872 KB Output is correct
13 Correct 21 ms 26872 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 26872 KB Output is correct
2 Correct 22 ms 27000 KB Output is correct
3 Correct 21 ms 26872 KB Output is correct
4 Correct 21 ms 26872 KB Output is correct
5 Correct 21 ms 26872 KB Output is correct
6 Correct 21 ms 26872 KB Output is correct
7 Correct 21 ms 27000 KB Output is correct
8 Correct 21 ms 26872 KB Output is correct
9 Correct 22 ms 26872 KB Output is correct
10 Correct 21 ms 26872 KB Output is correct
11 Correct 22 ms 26872 KB Output is correct
12 Correct 22 ms 27000 KB Output is correct
13 Correct 21 ms 27000 KB Output is correct
14 Correct 22 ms 26872 KB Output is correct
15 Correct 22 ms 26872 KB Output is correct
16 Correct 21 ms 26872 KB Output is correct
17 Correct 23 ms 27000 KB Output is correct
18 Correct 21 ms 27000 KB Output is correct
19 Correct 21 ms 27000 KB Output is correct
20 Correct 21 ms 27000 KB Output is correct
21 Correct 21 ms 27000 KB Output is correct
22 Correct 21 ms 27000 KB Output is correct
23 Correct 21 ms 27000 KB Output is correct
24 Correct 22 ms 26872 KB Output is correct
25 Correct 21 ms 26872 KB Output is correct
26 Correct 23 ms 26916 KB Output is correct
27 Correct 23 ms 27000 KB Output is correct
28 Correct 22 ms 26872 KB Output is correct
29 Correct 21 ms 26872 KB Output is correct
30 Correct 21 ms 26872 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 26872 KB Output is correct
2 Correct 21 ms 27000 KB Output is correct
3 Correct 22 ms 27000 KB Output is correct
4 Correct 22 ms 26872 KB Output is correct
5 Correct 21 ms 27000 KB Output is correct
6 Correct 21 ms 27000 KB Output is correct
7 Correct 22 ms 27000 KB Output is correct
8 Correct 23 ms 27000 KB Output is correct
9 Correct 22 ms 26872 KB Output is correct
10 Correct 22 ms 26872 KB Output is correct
11 Correct 22 ms 26872 KB Output is correct
12 Correct 21 ms 26872 KB Output is correct
13 Correct 21 ms 27000 KB Output is correct
14 Correct 21 ms 27000 KB Output is correct
15 Correct 21 ms 27000 KB Output is correct
16 Correct 21 ms 26872 KB Output is correct
17 Correct 21 ms 26872 KB Output is correct
18 Correct 21 ms 27000 KB Output is correct
19 Correct 21 ms 27004 KB Output is correct
20 Correct 21 ms 26872 KB Output is correct
21 Correct 21 ms 27000 KB Output is correct
22 Correct 21 ms 27000 KB Output is correct
23 Correct 22 ms 27000 KB Output is correct
24 Correct 21 ms 26872 KB Output is correct
25 Correct 22 ms 26872 KB Output is correct
26 Correct 21 ms 26872 KB Output is correct
27 Correct 22 ms 26872 KB Output is correct
28 Correct 21 ms 27000 KB Output is correct
29 Correct 22 ms 27000 KB Output is correct
30 Correct 21 ms 27000 KB Output is correct
31 Correct 22 ms 27000 KB Output is correct
32 Correct 26 ms 27384 KB Output is correct
33 Correct 25 ms 27384 KB Output is correct
34 Correct 22 ms 27260 KB Output is correct
35 Correct 23 ms 27128 KB Output is correct
36 Correct 25 ms 27256 KB Output is correct
37 Correct 24 ms 27256 KB Output is correct
38 Correct 24 ms 27256 KB Output is correct
39 Correct 22 ms 27128 KB Output is correct

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 28940 KB Output is correct
2 Correct 21 ms 26872 KB Output is correct
3 Correct 21 ms 26872 KB Output is correct
4 Correct 34 ms 28884 KB Output is correct
5 Correct 21 ms 26872 KB Output is correct
6 Correct 22 ms 26872 KB Output is correct
7 Correct 21 ms 27000 KB Output is correct
8 Correct 21 ms 26872 KB Output is correct
9 Correct 115 ms 43896 KB Output is correct
10 Correct 22 ms 27000 KB Output is correct
11 Correct 22 ms 27000 KB Output is correct
12 Correct 21 ms 26872 KB Output is correct
13 Correct 21 ms 26872 KB Output is correct
14 Correct 22 ms 26872 KB Output is correct
15 Correct 22 ms 27000 KB Output is correct
16 Correct 21 ms 27000 KB Output is correct
17 Correct 21 ms 26876 KB Output is correct
18 Correct 22 ms 26872 KB Output is correct
19 Correct 21 ms 26872 KB Output is correct
20 Correct 21 ms 26872 KB Output is correct
21 Correct 22 ms 27000 KB Output is correct
22 Correct 21 ms 27000 KB Output is correct
23 Correct 21 ms 26872 KB Output is correct
24 Correct 22 ms 27000 KB Output is correct
25 Correct 24 ms 27000 KB Output is correct
26 Correct 21 ms 26876 KB Output is correct
27 Correct 22 ms 26872 KB Output is correct
28 Correct 21 ms 26872 KB Output is correct
29 Correct 21 ms 27004 KB Output is correct
30 Correct 22 ms 27000 KB Output is correct
31 Correct 21 ms 26872 KB Output is correct
32 Correct 21 ms 27000 KB Output is correct
33 Correct 21 ms 26872 KB Output is correct
34 Correct 21 ms 27000 KB Output is correct
35 Correct 24 ms 27384 KB Output is correct
36 Correct 24 ms 27256 KB Output is correct
37 Correct 23 ms 27256 KB Output is correct
38 Correct 24 ms 27260 KB Output is correct
39 Correct 24 ms 27256 KB Output is correct
40 Correct 24 ms 27420 KB Output is correct
41 Correct 23 ms 27256 KB Output is correct
42 Correct 23 ms 27256 KB Output is correct
43 Correct 31 ms 27384 KB Output is correct
44 Execution timed out 1097 ms 34668 KB Time limit exceeded
45 Halted 0 ms 0 KB -