oj.uz

Submission #760575

# Submission time Handle Problem Language Result Execution time Memory
760575 2023-06-17T20:46:12 Z kingfran1907 Parking (CEOI22_parking) C++14
85 / 100
 285 ms 51300 KB 
#include <bits/stdc++.h>
#define X first
#define Y second

using namespace std;
typedef long long llint;

const int maxn = 3e5+10;
const int base = 31337;
const int mod = 1e9+7;
const int inf = 0x3f3f3f3f;
const int logo = 20;
const int off = 1 << logo;
const int treesiz = off << 1;

int n, m;
int niz[maxn][2];
vector< pair<int, int> > pos[maxn];
vector< pair<int, int> > sol;
int nex[maxn], rev[maxn];
bool bio[2 * maxn];
set< int > emps;
vector< int > graph[2 * maxn];
vector< vector< int > > chains, cycles;

void stop() {
	printf("-1\n");
	exit(0);
}

bool istop(pair<int, int> t) {
	int x = t.X;
	int wh = t.Y;
	if (wh == 1 || niz[x][1] == 0) return true;
	return false;
}

void move(int x, int y) {
	//printf("moving: %d %d\n", x + 1, y + 1);
	int ind1 = 0, ind2 = -1;
	if (niz[x][1] != 0) ind1 = 1;
	if (niz[y][0] == 0) ind2 = 0;
	else if (niz[y][1] == 0) ind2 = 1;
	assert(ind2 >= 0 && niz[x][ind1] != 0);

	sol.push_back({x + 1, y + 1});
	if (ind2 == 0) emps.erase(y);
	if (ind1 == 0) emps.insert(x);
	swap(niz[x][ind1], niz[y][ind2]);
}

void calc_pos() {
	emps.clear();
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < 2; j++) {
			if (niz[i][j] != 0) pos[niz[i][j]].push_back({i, j});
		}
		if (niz[i][0] == 0 && niz[i][1] == 0) emps.insert(i);
	}
}

vector< int > get_path(int x) {
	vector< int > v;
	int ptr = x;
	int las = -1;

	while (true) {
		bio[ptr] = true;
		v.push_back(ptr);
		bool flag = false;
		for (int tren : graph[ptr]) {
			if (tren != las && !bio[tren]) {
				las = ptr;
				ptr = tren;
				flag = true;
				break;
			}
		}
		if (!flag) break;
	}
	return v;
}

int price_chain(vector< int > &v) {
	int cnt = 0;
	for (int i = 0; i < v.size(); i += 2) {
		if (!istop({v[i + 1] / 2, v[i + 1] % 2})) cnt++;
	}
	if (cnt <= 1) return 0;

	cnt = 0;
	reverse(v.begin(), v.end());
	for (int i = 0; i < v.size(); i += 2) {
		if (!istop({v[i + 1] / 2, v[i + 1] % 2})) cnt++;
	} 
	reverse(v.begin(), v.end());
	if (cnt <= 1) return 0;
	return 1;
}

void solve_chain(vector< int > &v, int l, int r) {
	//printf("chain solving\n");
	if (l > r) return;
	for (int i = l; i <= r; i += 2) {
		if (v[i] % 2 == 1 && v[i + 1] % 2 == 1) {
			if (emps.empty()) stop();
			int ac = *emps.begin();

			move(v[i] / 2, ac);
			move(v[i + 1] / 2, ac);
			solve_chain(v, l, i - 1);
			solve_chain(v, i + 2, r);
			return;
		}
	}

	for (int i = l; i <= r; i += 2) {
		if (v[i] % 2 == 0 && v[i + 1] % 2 == 0) {
			for (int j = l; j < i; j += 2) 
				move(v[j + 1] / 2, v[j] / 2);
			for (int j = r; j > i + 1; j -= 2) 
				move(v[j - 1] / 2, v[j] / 2);
			move(v[i] / 2, v[i + 1] / 2);
			return;
		}
	}

	if (v[l + 1] % 2 == 1) {
		for (int i = l; i <= r; i += 2) 
			move(v[i + 1] / 2, v[i] / 2);
	} else {
		for (int i = r; i >= l; i -= 2) 
			move(v[i - 1] / 2, v[i] / 2);
	}
} 

inline int get(int x) {
	return niz[x / 2][x % 2];
}

int price_cycle(vector< int > &v) {
	for (int i = 0; i < v.size(); i++) {
		if (get(v[i]) == get(v[(i + 1) % v.size()]) && v[i] % 2 == 1 && v[i + 1] % 2 == 1) {
			vector< int > ne;
			for (int j = 0; j < v.size() - 2; j++) ne.push_back(v[(i + j + 2) % v.size()]);
			return price_chain(ne) + 1;
		}
	}
	return 1;
}

void solve_cycle(vector< int > &v) {
	//printf("cycle solving\n");
	for (int i = 0; i < v.size(); i++) {
		if (get(v[i]) == get(v[(i + 1) % v.size()]) && v[i] % 2 == 1 && v[i + 1] % 2 == 1) {
			vector< int > ne;
			for (int j = 0; j < v.size() - 2; j++) ne.push_back(v[(i + j + 2) % v.size()]);

			if (emps.empty()) stop();
			int x = *emps.begin();
			move(v[i] / 2, x);
			move(v[(i + 1) % v.size()] / 2, x);
			solve_chain(ne, 0, ne.size() - 1);
			return;
		}
	}

	if (emps.empty()) stop();
	int x = *emps.begin();
	int ind = -1;
	for (int i = 0; i < v.size(); i++) {
		if (v[i] % 2 == 1) ind = i;
	}

	move(v[ind] / 2, x);
	for (int i = 0; i < v.size() - 2; i += 2) {
		move(v[(ind + 2 + i) % v.size()] / 2, v[(ind + 1 + i) % v.size()] / 2);
	}
	move(v[(ind + v.size() - 1) % v.size()] / 2, x);
} 

int main() {
	scanf("%d%d", &n, &m);
	for (int i = 0; i < m; i++)
		for (int j = 0; j < 2; j++)
			scanf("%d", &niz[i][j]);
	
	calc_pos();
	for (int i = 1; i <= n; i++) {
		int ax = pos[i][0].X;
		int ay = pos[i][0].Y;
		int bx = pos[i][1].X;
		int by = pos[i][1].Y;

		graph[2 * ax + ay].push_back(2 * bx + by);
		graph[2 * bx + by].push_back(2 * ax + ay);
	}
	for (int i = 0; i < m; i++) {
		if (niz[i][0] > 0 && niz[i][1] > 0 && niz[i][0] != niz[i][1]) {
			graph[i * 2].push_back(2 * i + 1);
			graph[i * 2 + 1].push_back(2 * i);
		}
	}

	for (int i = 0; i < 2 * m; i++) {
		if (graph[i].size() == 1 && !bio[i]) {
			vector< int > v = get_path(i);
			//printf("chain: ");
			//for (int tren : v) printf("%d ", tren);
			//printf("\n");

			if (v.size() == 2) {
				if (v[0] / 2 == v[1] / 2) continue;
				move(v[0] / 2, v[1] / 2);
				continue;
			}
			chains.push_back(v);
		}
	}

	for (int i = 0; i < 2 * m; i++) {
		if (!bio[i] && graph[i].size() == 2) {
			vector< int > v = get_path(i);
			//printf("cycle: ");
			//for (int tren : v) printf("%d ", tren);
			//printf("\n");

			cycles.push_back(v);
		} 
	}

	vector< vector< int > > tr;
	for (auto &iter : chains) {
		if (price_chain(iter) == 0) solve_chain(iter, 0, iter.size() - 1);
		else tr.push_back(iter);
	}
	for (auto &iter : tr) solve_chain(iter, 0, iter.size() - 1);

	tr.clear();
	for (auto &iter : cycles) {
		if (price_cycle(iter) == 1) solve_cycle(iter);
		else tr.push_back(iter);
	}
	for (auto &iter : tr) solve_cycle(iter);

	printf("%d\n", sol.size());
	for (auto iter : sol) printf("%d %d\n", iter.X, iter.Y);
	return 0;
}

Compilation message

Main.cpp: In function 'int price_chain(std::vector<int>&)':
Main.cpp:86:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |  for (int i = 0; i < v.size(); i += 2) {
      |                  ~~^~~~~~~~~~
Main.cpp:93:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |  for (int i = 0; i < v.size(); i += 2) {
      |                  ~~^~~~~~~~~~
Main.cpp: In function 'int price_cycle(std::vector<int>&)':
Main.cpp:142:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  142 |  for (int i = 0; i < v.size(); i++) {
      |                  ~~^~~~~~~~~~
Main.cpp:145:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  145 |    for (int j = 0; j < v.size() - 2; j++) ne.push_back(v[(i + j + 2) % v.size()]);
      |                    ~~^~~~~~~~~~~~~~
Main.cpp: In function 'void solve_cycle(std::vector<int>&)':
Main.cpp:154:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  154 |  for (int i = 0; i < v.size(); i++) {
      |                  ~~^~~~~~~~~~
Main.cpp:157:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  157 |    for (int j = 0; j < v.size() - 2; j++) ne.push_back(v[(i + j + 2) % v.size()]);
      |                    ~~^~~~~~~~~~~~~~
Main.cpp:171:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  171 |  for (int i = 0; i < v.size(); i++) {
      |                  ~~^~~~~~~~~~
Main.cpp:176:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  176 |  for (int i = 0; i < v.size() - 2; i += 2) {
      |                  ~~^~~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:246:11: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wformat=]
  246 |  printf("%d\n", sol.size());
      |          ~^     ~~~~~~~~~~
      |           |             |
      |           int           std::vector<std::pair<int, int> >::size_type {aka long unsigned int}
      |          %ld
Main.cpp:183:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  183 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
Main.cpp:186:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  186 |    scanf("%d", &niz[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 21332 KB Output is correct
2 Correct 11 ms 21448 KB Output is correct
3 Correct 12 ms 21332 KB Output is correct
4 Correct 10 ms 21332 KB Output is correct
5 Correct 12 ms 21332 KB Output is correct
6 Correct 11 ms 21368 KB Output is correct
7 Correct 11 ms 21400 KB Output is correct
8 Correct 12 ms 21400 KB Output is correct
9 Correct 11 ms 21332 KB Output is correct
10 Correct 11 ms 21332 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 165 ms 38928 KB Output is correct
2 Correct 160 ms 40708 KB Output is correct
3 Correct 127 ms 37016 KB Output is correct
4 Correct 117 ms 36576 KB Output is correct
5 Correct 156 ms 40772 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21460 KB Output is correct
2 Correct 11 ms 21444 KB Output is correct
3 Correct 11 ms 21496 KB Output is correct
4 Correct 11 ms 21480 KB Output is correct
5 Correct 11 ms 21460 KB Output is correct
6 Correct 11 ms 21460 KB Output is correct
7 Correct 11 ms 21588 KB Output is correct
8 Correct 12 ms 21484 KB Output is correct
9 Correct 12 ms 21576 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21460 KB Output is correct
2 Correct 11 ms 21444 KB Output is correct
3 Correct 11 ms 21496 KB Output is correct
4 Correct 11 ms 21480 KB Output is correct
5 Correct 11 ms 21460 KB Output is correct
6 Correct 11 ms 21460 KB Output is correct
7 Correct 11 ms 21588 KB Output is correct
8 Correct 12 ms 21484 KB Output is correct
9 Correct 12 ms 21576 KB Output is correct
10 Correct 266 ms 51300 KB Output is correct
11 Correct 153 ms 41568 KB Output is correct
12 Correct 197 ms 43052 KB Output is correct
13 Correct 254 ms 47428 KB Output is correct
14 Correct 213 ms 44824 KB Output is correct
15 Correct 213 ms 44412 KB Output is correct
16 Correct 285 ms 50520 KB Output is correct
17 Correct 203 ms 44236 KB Output is correct
18 Correct 255 ms 49036 KB Output is correct

Subtask #5
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 21588 KB Output is correct
2 Correct 11 ms 21528 KB Output is correct
3 Correct 11 ms 21532 KB Output is correct
4 Correct 11 ms 21468 KB Output is correct
5 Correct 11 ms 21508 KB Output is correct
6 Correct 11 ms 21460 KB Output is correct
7 Correct 13 ms 21460 KB Output is correct
8 Correct 11 ms 21600 KB Output is correct
9 Correct 12 ms 21588 KB Output is correct
10 Correct 11 ms 21520 KB Output is correct
11 Correct 13 ms 21588 KB Output is correct
12 Correct 11 ms 21460 KB Output is correct
13 Correct 11 ms 21504 KB Output is correct
14 Correct 11 ms 21564 KB Output is correct
15 Correct 11 ms 21460 KB Output is correct
16 Correct 11 ms 21552 KB Output is correct
17 Correct 13 ms 21572 KB Output is correct
18 Correct 11 ms 21588 KB Output is correct
19 Correct 11 ms 21584 KB Output is correct
20 Correct 15 ms 21512 KB Output is correct
21 Correct 11 ms 21460 KB Output is correct
22 Correct 12 ms 21592 KB Output is correct
23 Correct 12 ms 21576 KB Output is correct
24 Correct 12 ms 21588 KB Output is correct

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 21332 KB Output is correct
2 Correct 11 ms 21448 KB Output is correct
3 Correct 12 ms 21332 KB Output is correct
4 Correct 10 ms 21332 KB Output is correct
5 Correct 12 ms 21332 KB Output is correct
6 Correct 11 ms 21368 KB Output is correct
7 Correct 11 ms 21400 KB Output is correct
8 Correct 12 ms 21400 KB Output is correct
9 Correct 11 ms 21332 KB Output is correct
10 Correct 11 ms 21332 KB Output is correct
11 Correct 165 ms 38928 KB Output is correct
12 Correct 160 ms 40708 KB Output is correct
13 Correct 127 ms 37016 KB Output is correct
14 Correct 117 ms 36576 KB Output is correct
15 Correct 156 ms 40772 KB Output is correct
16 Correct 10 ms 21460 KB Output is correct
17 Correct 11 ms 21444 KB Output is correct
18 Correct 11 ms 21496 KB Output is correct
19 Correct 11 ms 21480 KB Output is correct
20 Correct 11 ms 21460 KB Output is correct
21 Correct 11 ms 21460 KB Output is correct
22 Correct 11 ms 21588 KB Output is correct
23 Correct 12 ms 21484 KB Output is correct
24 Correct 12 ms 21576 KB Output is correct
25 Correct 266 ms 51300 KB Output is correct
26 Correct 153 ms 41568 KB Output is correct
27 Correct 197 ms 43052 KB Output is correct
28 Correct 254 ms 47428 KB Output is correct
29 Correct 213 ms 44824 KB Output is correct
30 Correct 213 ms 44412 KB Output is correct
31 Correct 285 ms 50520 KB Output is correct
32 Correct 203 ms 44236 KB Output is correct
33 Correct 255 ms 49036 KB Output is correct
34 Correct 13 ms 21588 KB Output is correct
35 Correct 11 ms 21528 KB Output is correct
36 Correct 11 ms 21532 KB Output is correct
37 Correct 11 ms 21468 KB Output is correct
38 Correct 11 ms 21508 KB Output is correct
39 Correct 11 ms 21460 KB Output is correct
40 Correct 13 ms 21460 KB Output is correct
41 Correct 11 ms 21600 KB Output is correct
42 Correct 12 ms 21588 KB Output is correct
43 Correct 11 ms 21520 KB Output is correct
44 Correct 13 ms 21588 KB Output is correct
45 Correct 11 ms 21460 KB Output is correct
46 Correct 11 ms 21504 KB Output is correct
47 Correct 11 ms 21564 KB Output is correct
48 Correct 11 ms 21460 KB Output is correct
49 Correct 11 ms 21552 KB Output is correct
50 Correct 13 ms 21572 KB Output is correct
51 Correct 11 ms 21588 KB Output is correct
52 Correct 11 ms 21584 KB Output is correct
53 Correct 15 ms 21512 KB Output is correct
54 Correct 11 ms 21460 KB Output is correct
55 Correct 12 ms 21592 KB Output is correct
56 Correct 12 ms 21576 KB Output is correct
57 Correct 12 ms 21588 KB Output is correct
58 Correct 240 ms 48512 KB Output is correct
59 Correct 251 ms 49752 KB Output is correct
60 Correct 215 ms 46532 KB Output is correct
61 Correct 260 ms 48144 KB Output is correct
62 Correct 146 ms 42068 KB Output is correct
63 Correct 227 ms 48408 KB Output is correct
64 Correct 203 ms 43556 KB Output is correct
65 Correct 238 ms 49108 KB Output is correct
66 Incorrect 206 ms 43840 KB Output isn't correct
67 Halted 0 ms 0 KB -