Submission #684852

#	Time	Username	Problem	Language	Result	Execution time	Memory
684852		US3RN4M3	T-Covering (eJOI19_covering)	C++17	100 / 100	314 ms	47804 KiB

covering

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int mx = 1005;
int val[mx*mx];
int sid[mx*mx];
bool g_vis[mx*mx];
int n, m;
int dx1[4] = {1, 1, 1, 0};
int dy1[4] = {1, 0, -1, 1};
int dx2[2] = {2, 0};
int dy2[2] = {0, 2};
int dx3[4] = {1, -1, 0, 0};
int dy3[4] = {0, 0, 1, -1};
int dx4[5] = {0, 1, -1, 0, 0};
int dy4[5] = {0, 0, 0, -1, 1};
vector<pair<int, int>> heavy_edges;
vector<pair<int, int>> light_edges;
int g_idx[mx*mx];
vector<int> g_vec[mx*mx];
int g_best[mx*mx];
int g_bad[mx*mx];
void add_light(int a, int b) {
	g_bad[g_idx[b]]++;
	if(g_idx[a] == g_idx[b]) return;
	if(g_vec[g_idx[a]].size() > g_vec[g_idx[b]].size()) swap(a, b);
	g_best[g_idx[b]] = min(g_best[g_idx[b]], g_best[g_idx[a]]);
	g_bad[g_idx[b]] += g_bad[g_idx[a]];
	vector<int> & a_vec = g_vec[g_idx[a]];
	for(int i : a_vec) {
		g_idx[i] = g_idx[b];
		g_vec[g_idx[b]].push_back(i);
	}
}
void add_heavy(int a, int b) {
	add_light(a, b);
	g_bad[g_idx[b]]++;
}
main() {
	cin >> n >> m;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			cin >> val[i*m + j];
		}
	}
	int cnt_spec;
	cin >> cnt_spec;
	vector<pair<int, int>> spec(cnt_spec + 1);
	for(int i = 1; i <= cnt_spec; i++) {
		int x, y; cin >> x >> y;
		spec[i] = {x, y};
		sid[x*m + y] = i;
	}
	for(int i = 1; i <= cnt_spec; i++) {
		auto [x, y] = spec[i];
		for(int dir = 0; dir < 4; dir++) {
			int nx = x + dx1[dir];
			int ny = y + dy1[dir];
			if(nx < 0 || ny < 0 || nx >= n || ny >= m) continue;
			if(!sid[nx*m + ny]) continue;
			heavy_edges.push_back({i, sid[nx*m + ny]});
			//if(i == 9) cout << sid[nx][ny] << "," << endl << nx << " " << ny << endl;
			//if(sid[nx][ny] == 9) cout << i << "." << endl << nx << " " << ny << endl;
		}
		for(int dir = 0; dir < 2; dir++) {
			int nx = x + dx2[dir];
			int ny = y + dy2[dir];
			if(nx < 0 || ny < 0 || nx >= n || ny >= m) continue;
			if(!sid[nx*m + ny]) continue;
			light_edges.push_back({i, sid[nx*m + ny]});
		}
	}
	for(int i = 1; i <= cnt_spec; i++) {
		g_idx[i] = i;
		g_vec[i] = {i};
		g_best[i] = 1e9;
		g_bad[i] = 0;
		auto [x, y] = spec[i];
		for(int dir = 0; dir < 4; dir++) {
			int nx = x + dx3[dir];
			int ny = y + dy3[dir];
			if(nx < 0 || ny < 0 || nx >= n || ny >= m) {
				g_bad[i]++;
			} else g_best[i] = min(g_best[i], val[nx*m + ny]);
		}
	}
	for(auto [a, b] : light_edges) add_light(a, b);
	for(auto [a, b] : heavy_edges) add_heavy(a, b);
	ll rem = 0;
	for(int i = 1; i <= cnt_spec; i++) {
		int id = g_idx[i];
		if(g_vis[id]) continue;
		g_vis[id] = true;
		if(g_bad[id] > g_vec[id].size()) {
			cout << "No" << endl;
			return 0;
			cout << g_bad[id] << ": " << g_vec[id].size() << endl;
			for(int j = 0; j < g_vec[id].size(); j++) {
				int k = g_vec[id][j];
				cout << k << ": ";
				cout << spec[k].first << " " << spec[k].second << endl;
			}
			return 0;
		}
		if(g_bad[id] == g_vec[id].size()) continue;
		rem += g_best[id];
	}
	ll ans = 0;
	for(int i = 0; i < n; i++) for(int j = 0; j < m; j++) {
		bool cond = false;
		for(int dir = 0; dir < 5; dir++) {
			int nx = i + dx4[dir];
			int ny = j + dy4[dir];
			if(nx < 0 || ny < 0 || nx >= n || ny >= m) continue;
			if(sid[nx*m + ny]) cond = true;
		}
		if(cond) ans += val[i*m + j];
	}
	ans -= rem;
	cout << ans << endl;
}

Compilation message (stderr)

covering.cpp:39:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   39 | main() {
      | ^~~~
covering.cpp: In function 'int main()':
covering.cpp:94:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |   if(g_bad[id] > g_vec[id].size()) {
      |      ~~~~~~~~~~^~~~~~~~~~~~~~~~~~
covering.cpp:98:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |    for(int j = 0; j < g_vec[id].size(); j++) {
      |                   ~~^~~~~~~~~~~~~~~~~~
covering.cpp:105:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |   if(g_bad[id] == g_vec[id].size()) continue;
      |      ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 30 / 30