Submission #794524

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
794524	2023-07-26T15:20:19 Z	peijar	Virus Experiment (JOI19_virus)	C++17	100 / 100	672 ms	32160 KB

virus

#include <bits/stdc++.h>
#define int long long
using namespace std;
 
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define sz(v) ((int)((v).size()))
 
template<typename T>
void chmax(T &x, const T &v) { if (x < v) x = v; }
template<typename T>
void chmin(T &x, const T &v) { if (x > v) x = v; }
 
using pii = pair<int, int>;
using vi = vector<int>;
 
string to_string(string s) { return s; }
template <typename T> string to_string(T v) {
	bool first = true;
	string res = "[";
	for (const auto &x : v) {
		if (!first)
			res += ", ";
		first = false;
		res += to_string(x);
	}
	res += "]";
	return res;
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
	cout << ' ' << to_string(H);
	dbg_out(T...);
}
 
#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif
 
const int MAX_THRESHOLD = 1e5 + 5; // U
const int MAX_DIM = 805;
const int MAX_CASE = MAX_DIM * MAX_DIM;
int M, R, C;
string meteo;
int U[MAX_DIM][MAX_DIM];
 
int numero(int l, int c) {
	return l*C + c;
}
 
pii ligCol(int cell) {
	return {cell/C, cell % C};
}
int drepr[MAX_CASE], dsz[MAX_CASE];
void init() {
	rep(i, 0, R*C) {
		drepr[i] = i;
		dsz[i] = 1;
	}
}
int find(int a) {
	if (drepr[a] == a) return a;
	return drepr[a] = find(drepr[a]);
}
 
void unite(int parent, int child) {
	parent = find(parent), child = find(child);
	if (parent == child) return;
	drepr[child] = parent;
	dsz[parent] += dsz[child];
}
 
int mapChar[256];
int bestSeg[1 << 4];
void calcSeg() {
	rep(mask, 0, 16) {
		int best = 0, cur = 0;
		for (char c : meteo) {
			if ((1 << mapChar[c]) & mask) {
				++cur;
			} else {
				cur = 0;
			}
			chmax(best, cur);
		}
		if (best >= M) best = MAX_THRESHOLD;
		bestSeg[mask] = best;
	}
}
 
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> M >> R >> C;
	cin >> meteo;
	meteo.append(meteo);
	mapChar['N'] = 0, mapChar['W'] = 1, mapChar['E'] = 2, mapChar['S'] = 3;
	vector<int> deltas(256);
	deltas['N'] = C, deltas['S'] = -C; // l*C + c
	if (C > 1) {
		deltas['W'] = 1, deltas['E'] = -1;
	}
	calcSeg();
	// rep(mask, 0, 16) {
	// 	dbg(mask, bestSeg[mask]);
	// }
	rep(i, 0, R) rep(j, 0, C) {
		cin >> U[i][j];
	}
	init();
	priority_queue<pii, vector<pii>, greater<pii>> pq;
	rep(lig, 0, R) rep(col, 0, C) {
		if (U[lig][col] != 0) {
			pq.push({1, numero(lig, col)});
		}
	}
 
	auto getVoisins = [&] (int cell) {
		vector<int> voisins;
		auto [lig, col] = ligCol(cell);
		rep(dl, -1, 2) rep(dc, -1, 2) if ((dl==0)^(dc==0)) {
			int nl = lig+dl, nc = col+dc;
			if (nl >= 0 && nl < R && nc >= 0 && nc < C && U[nl][nc] != 0) {
				voisins.push_back(numero(nl, nc));
			}
			}
		return voisins;
	};
 
	int best = 1e9;
	int nbBest = 0;
	auto updAns = [&] (int proposal) {
		if (proposal < best) {
			best = proposal, nbBest = 1;
		} else if (proposal == best) {
			++nbBest;
		}
	};
	vector<int> isInfected(R*C);
	vector<bool> mark(R*C, false);
	int timeInf = 0;
	auto discover = [&] (int depart) {
		int compDepart = find(depart);
		++timeInf;
		queue<int> bfs;
		isInfected[depart] = timeInf;
		for (int v : getVoisins(depart)) {
			bfs.push(v);
		}
		int nbSeen = 1; // compte depart
		while (!bfs.empty()) {
			int cur = bfs.front();
			bfs.pop();
			if (isInfected[cur] == timeInf) continue;
			dbg(depart, "voit"s, cur);
			int mask = 0;
			for (int v : getVoisins(cur)) {
				if (isInfected[v] != timeInf) continue;
				int diff = cur - v;
				char dir = '~';
				for (char c : "NWSE") {
					if (diff == deltas[c]) dir = c;
				}
				assert(dir != '~');
				mask += 1 << mapChar[dir];
			}
			auto [lig, col] = ligCol(cur);
			if (U[lig][col] <= bestSeg[mask]) {
				int compCur = find(cur);
				if (compCur != compDepart) {
					if (mark[compCur]) {
						mark[compDepart] = true;
						return;
					}
					// merge depart dans cur
					unite(cur, depart);
					pq.push({dsz[compCur], compCur});
					return;
				}
				isInfected[cur] = timeInf;
				++nbSeen;
				for (int v : getVoisins(cur)) {
					bfs.push(v);
				}
			}
		}
		// composante stable
		updAns(nbSeen);
		dbg(depart, compDepart, "stable"s);
		mark[compDepart] = true;
	};
	while (!pq.empty()) {
		auto [szCell, cell] = pq.top();
		pq.pop();
		if (szCell != dsz[cell]) continue;
		discover(cell);
	}
	cout << best << '\n';
	cout << nbBest*best << '\n';
}

Compilation message

virus.cpp: In function 'void calcSeg()':
virus.cpp:88:22: warning: array subscript has type 'char' [-Wchar-subscripts]
   88 |    if ((1 << mapChar[c]) & mask) {
      |                      ^
virus.cpp: In lambda function:
virus.cpp:174:26: warning: array subscript has type 'char' [-Wchar-subscripts]
  174 |     mask += 1 << mapChar[dir];
      |                          ^~~

Subtask #1

14.0 / 14.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	596 KB	Output is correct
2	Correct	483 ms	31936 KB	Output is correct
3	Correct	483 ms	31852 KB	Output is correct
4	Correct	292 ms	31916 KB	Output is correct
5	Correct	428 ms	31968 KB	Output is correct
6	Correct	2 ms	3540 KB	Output is correct
7	Correct	626 ms	32104 KB	Output is correct
8	Correct	160 ms	13160 KB	Output is correct

Subtask #2

6.0 / 6.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	340 KB	Output is correct
2	Correct	5 ms	724 KB	Output is correct
3	Correct	4 ms	724 KB	Output is correct
4	Correct	5 ms	724 KB	Output is correct
5	Correct	5 ms	724 KB	Output is correct
6	Correct	6 ms	888 KB	Output is correct
7	Correct	1 ms	340 KB	Output is correct
8	Correct	5 ms	760 KB	Output is correct
9	Correct	2 ms	596 KB	Output is correct
10	Correct	4 ms	724 KB	Output is correct
11	Correct	2 ms	596 KB	Output is correct
12	Correct	2 ms	724 KB	Output is correct
13	Correct	6 ms	888 KB	Output is correct
14	Correct	6 ms	888 KB	Output is correct
15	Correct	6 ms	888 KB	Output is correct
16	Correct	6 ms	888 KB	Output is correct
17	Correct	4 ms	852 KB	Output is correct
18	Correct	3 ms	664 KB	Output is correct
19	Correct	6 ms	888 KB	Output is correct

Subtask #3

80.0 / 80.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	596 KB	Output is correct
2	Correct	483 ms	31936 KB	Output is correct
3	Correct	483 ms	31852 KB	Output is correct
4	Correct	292 ms	31916 KB	Output is correct
5	Correct	428 ms	31968 KB	Output is correct
6	Correct	2 ms	3540 KB	Output is correct
7	Correct	626 ms	32104 KB	Output is correct
8	Correct	160 ms	13160 KB	Output is correct
9	Correct	0 ms	340 KB	Output is correct
10	Correct	5 ms	724 KB	Output is correct
11	Correct	4 ms	724 KB	Output is correct
12	Correct	5 ms	724 KB	Output is correct
13	Correct	5 ms	724 KB	Output is correct
14	Correct	6 ms	888 KB	Output is correct
15	Correct	1 ms	340 KB	Output is correct
16	Correct	5 ms	760 KB	Output is correct
17	Correct	2 ms	596 KB	Output is correct
18	Correct	4 ms	724 KB	Output is correct
19	Correct	2 ms	596 KB	Output is correct
20	Correct	2 ms	724 KB	Output is correct
21	Correct	6 ms	888 KB	Output is correct
22	Correct	6 ms	888 KB	Output is correct
23	Correct	6 ms	888 KB	Output is correct
24	Correct	6 ms	888 KB	Output is correct
25	Correct	4 ms	852 KB	Output is correct
26	Correct	3 ms	664 KB	Output is correct
27	Correct	6 ms	888 KB	Output is correct
28	Correct	487 ms	32112 KB	Output is correct
29	Correct	388 ms	32092 KB	Output is correct
30	Correct	395 ms	32056 KB	Output is correct
31	Correct	477 ms	31468 KB	Output is correct
32	Correct	483 ms	31688 KB	Output is correct
33	Correct	315 ms	31928 KB	Output is correct
34	Correct	672 ms	31904 KB	Output is correct
35	Correct	377 ms	23428 KB	Output is correct
36	Correct	621 ms	31940 KB	Output is correct
37	Correct	508 ms	31880 KB	Output is correct
38	Correct	464 ms	31896 KB	Output is correct
39	Correct	497 ms	32160 KB	Output is correct
40	Correct	541 ms	32092 KB	Output is correct
41	Correct	231 ms	32120 KB	Output is correct
42	Correct	383 ms	26772 KB	Output is correct
43	Correct	395 ms	32144 KB	Output is correct
44	Correct	147 ms	13172 KB	Output is correct