oj.uz

Submission #760576

# Submission time Handle Problem Language Result Execution time Memory
760576 2023-06-17T20:54:04 Z kingfran1907 Parking (CEOI22_parking) C++14
85 / 100
 298 ms 100632 KB 
#include <bits/stdc++.h>
#define X first
#define Y second

using namespace std;
typedef long long llint;

const int maxn = 1e6+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 36 ms 70732 KB Output is correct
2 Correct 30 ms 70716 KB Output is correct
3 Correct 31 ms 70708 KB Output is correct
4 Correct 32 ms 70740 KB Output is correct
5 Correct 31 ms 70724 KB Output is correct
6 Correct 32 ms 70772 KB Output is correct
7 Correct 33 ms 70732 KB Output is correct
8 Correct 33 ms 70764 KB Output is correct
9 Correct 33 ms 70812 KB Output is correct
10 Correct 32 ms 70740 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 149 ms 88240 KB Output is correct
2 Correct 174 ms 90008 KB Output is correct
3 Correct 136 ms 86284 KB Output is correct
4 Correct 145 ms 85976 KB Output is correct
5 Correct 186 ms 90036 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 70772 KB Output is correct
2 Correct 33 ms 70840 KB Output is correct
3 Correct 37 ms 70824 KB Output is correct
4 Correct 33 ms 70872 KB Output is correct
5 Correct 33 ms 70828 KB Output is correct
6 Correct 35 ms 70800 KB Output is correct
7 Correct 34 ms 70912 KB Output is correct
8 Correct 33 ms 70868 KB Output is correct
9 Correct 34 ms 70860 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 70772 KB Output is correct
2 Correct 33 ms 70840 KB Output is correct
3 Correct 37 ms 70824 KB Output is correct
4 Correct 33 ms 70872 KB Output is correct
5 Correct 33 ms 70828 KB Output is correct
6 Correct 35 ms 70800 KB Output is correct
7 Correct 34 ms 70912 KB Output is correct
8 Correct 33 ms 70868 KB Output is correct
9 Correct 34 ms 70860 KB Output is correct
10 Correct 297 ms 100632 KB Output is correct
11 Correct 175 ms 90868 KB Output is correct
12 Correct 256 ms 92528 KB Output is correct
13 Correct 279 ms 96808 KB Output is correct
14 Correct 238 ms 94060 KB Output is correct
15 Correct 214 ms 93736 KB Output is correct
16 Correct 289 ms 99828 KB Output is correct
17 Correct 232 ms 93508 KB Output is correct
18 Correct 268 ms 98388 KB Output is correct

Subtask #5
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 70792 KB Output is correct
2 Correct 33 ms 70896 KB Output is correct
3 Correct 34 ms 70884 KB Output is correct
4 Correct 38 ms 70752 KB Output is correct
5 Correct 33 ms 70772 KB Output is correct
6 Correct 33 ms 70888 KB Output is correct
7 Correct 33 ms 70788 KB Output is correct
8 Correct 33 ms 70888 KB Output is correct
9 Correct 33 ms 70792 KB Output is correct
10 Correct 32 ms 70832 KB Output is correct
11 Correct 39 ms 70896 KB Output is correct
12 Correct 33 ms 70784 KB Output is correct
13 Correct 33 ms 70732 KB Output is correct
14 Correct 33 ms 70868 KB Output is correct
15 Correct 34 ms 70832 KB Output is correct
16 Correct 34 ms 70868 KB Output is correct
17 Correct 34 ms 70784 KB Output is correct
18 Correct 34 ms 70868 KB Output is correct
19 Correct 33 ms 70860 KB Output is correct
20 Correct 34 ms 70892 KB Output is correct
21 Correct 40 ms 70800 KB Output is correct
22 Correct 34 ms 70884 KB Output is correct
23 Correct 32 ms 70824 KB Output is correct
24 Correct 33 ms 70896 KB Output is correct

Subtask #6
0.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 70732 KB Output is correct
2 Correct 30 ms 70716 KB Output is correct
3 Correct 31 ms 70708 KB Output is correct
4 Correct 32 ms 70740 KB Output is correct
5 Correct 31 ms 70724 KB Output is correct
6 Correct 32 ms 70772 KB Output is correct
7 Correct 33 ms 70732 KB Output is correct
8 Correct 33 ms 70764 KB Output is correct
9 Correct 33 ms 70812 KB Output is correct
10 Correct 32 ms 70740 KB Output is correct
11 Correct 149 ms 88240 KB Output is correct
12 Correct 174 ms 90008 KB Output is correct
13 Correct 136 ms 86284 KB Output is correct
14 Correct 145 ms 85976 KB Output is correct
15 Correct 186 ms 90036 KB Output is correct
16 Correct 38 ms 70772 KB Output is correct
17 Correct 33 ms 70840 KB Output is correct
18 Correct 37 ms 70824 KB Output is correct
19 Correct 33 ms 70872 KB Output is correct
20 Correct 33 ms 70828 KB Output is correct
21 Correct 35 ms 70800 KB Output is correct
22 Correct 34 ms 70912 KB Output is correct
23 Correct 33 ms 70868 KB Output is correct
24 Correct 34 ms 70860 KB Output is correct
25 Correct 297 ms 100632 KB Output is correct
26 Correct 175 ms 90868 KB Output is correct
27 Correct 256 ms 92528 KB Output is correct
28 Correct 279 ms 96808 KB Output is correct
29 Correct 238 ms 94060 KB Output is correct
30 Correct 214 ms 93736 KB Output is correct
31 Correct 289 ms 99828 KB Output is correct
32 Correct 232 ms 93508 KB Output is correct
33 Correct 268 ms 98388 KB Output is correct
34 Correct 36 ms 70792 KB Output is correct
35 Correct 33 ms 70896 KB Output is correct
36 Correct 34 ms 70884 KB Output is correct
37 Correct 38 ms 70752 KB Output is correct
38 Correct 33 ms 70772 KB Output is correct
39 Correct 33 ms 70888 KB Output is correct
40 Correct 33 ms 70788 KB Output is correct
41 Correct 33 ms 70888 KB Output is correct
42 Correct 33 ms 70792 KB Output is correct
43 Correct 32 ms 70832 KB Output is correct
44 Correct 39 ms 70896 KB Output is correct
45 Correct 33 ms 70784 KB Output is correct
46 Correct 33 ms 70732 KB Output is correct
47 Correct 33 ms 70868 KB Output is correct
48 Correct 34 ms 70832 KB Output is correct
49 Correct 34 ms 70868 KB Output is correct
50 Correct 34 ms 70784 KB Output is correct
51 Correct 34 ms 70868 KB Output is correct
52 Correct 33 ms 70860 KB Output is correct
53 Correct 34 ms 70892 KB Output is correct
54 Correct 40 ms 70800 KB Output is correct
55 Correct 34 ms 70884 KB Output is correct
56 Correct 32 ms 70824 KB Output is correct
57 Correct 33 ms 70896 KB Output is correct
58 Correct 250 ms 97900 KB Output is correct
59 Correct 261 ms 99016 KB Output is correct
60 Correct 229 ms 95772 KB Output is correct
61 Correct 298 ms 97376 KB Output is correct
62 Correct 169 ms 91456 KB Output is correct
63 Correct 282 ms 97748 KB Output is correct
64 Correct 260 ms 92936 KB Output is correct
65 Correct 249 ms 98536 KB Output is correct
66 Incorrect 243 ms 93208 KB Output isn't correct
67 Halted 0 ms 0 KB -