Submission #489654

#	Time	Username	Problem	Language	Result	Execution time	Memory
489654		fhvirus	Virus Experiment (JOI19_virus)	C++17	100 / 100	927 ms	18020 KiB

virus

// Knapsack DP is harder than FFT.
#include<bits/stdc++.h>
using namespace std;
typedef long long ll; typedef pair<int,int> pii; typedef pair<ll,ll> pll;
#define ff first
#define ss second
#define pb emplace_back
#define AI(x) begin(x),end(x)
template<class I>bool chmax(I&a,I b){return a<b?(a=b,true):false;}
template<class I>bool chmin(I&a,I b){return b<a?(a=b,true):false;} 
#ifdef OWO
#define debug(args...) SDF(#args, args)
#define OIU(args...) ostream& operator<<(ostream&O,args)
#define LKJ(S,B,E,F) template<class...T>OIU(S<T...>s){O<<B;int c=0;for(auto i:s)O<<(c++?", ":"")<<F;return O<<E;}
LKJ(vector,'[',']',i)LKJ(deque,'[',']',i)LKJ(set,'{','}',i)LKJ(multiset,'{','}',i)LKJ(unordered_set,'{','}',i)LKJ(map,'{','}',i.ff<<':'<<i.ss)LKJ(unordered_map,'{','}',i.ff<<':'<<i.ss)
template<class...T>void SDF(const char* s,T...a){int c=sizeof...(T);if(!c){cerr<<"\033[1;32mvoid\033[0m\n";return;}(cerr<<"\033[1;32m("<<s<<") = (",...,(cerr<<a<<(--c?", ":")\033[0m\n")));}
template<class T,size_t N>OIU(array<T,N>a){return O<<vector<T>(AI(a));}template<class...T>OIU(pair<T...>p){return O<<'('<<p.ff<<','<<p.ss<<')';}template<class...T>OIU(tuple<T...>t){return O<<'(',apply([&O](T...s){int c=0;(...,(O<<(c++?", ":"")<<s));},t),O<<')';}
#else
#pragma GCC optimize("Ofast")
#define debug(...) ((void)0)
#endif

const int INF = 8e7;
const int dc[4] = { 'N', 'S', 'W', 'E' };
const int dx[4] = {  -1,   1,   0,   0 };
const int dy[4] = {   0,   0,  -1,   1 };
[[ gnu::pure ]] int ctod(char c){
	for(int k = 0; k < 4; ++k){
		if(c == dc[k])
			return k;
	}
	return -1;
}

signed main(){
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	// input
	int M, R, C;
	cin >> M >> R >> C;
	string D; cin >> D;
	vector<vector<int>> U(R, vector<int>(C));
	for(vector<int> &v: U)
		for(int &i: v) cin >> i;

	// preprocess D
	D += D;
	vector<int> pre(16, 0);
	vector<int> thr(16, 0);
	for(int i = 0; i < M*2; ++i){
		for(int j = 1; j < 16; ++j)
			if(j >> ctod(D[i]) & 1){
				++pre[j];
				chmax(thr[j], pre[j]);
			} else pre[j] = 0;
	}
	for(int j = 1; j < 16; ++j)
		if(thr[j] == M*2) thr[j] = INF;

	vector<pii> perm(R*C);
	for(int i = 0, k = 0; i < R; ++i)
		for(int j = 0; j < C; ++j, ++k)
			perm[k] = pii(i, j);
	shuffle(AI(perm), mt19937(random_device()()));

	int mnv = INF, mnc = 0;
	vector<vector<bool>> owr(R, vector<bool>(C, false));
	vector<vector<bool>> vis(R, vector<bool>(C, false));
	function<bool(int, int)> inside = [&](int r, int c){
		return (0 <= r and r < R and 0 <= c and c < C);
	};
	function<bool(int, int)> infect = [&](int r, int c){
		if(U[r][c] == 0) return false;
		int msk = 0;
		for(int x, y, d = 0; d < 4; ++d){
			x = r + dx[d]; y = c + dy[d];
			if(inside(x, y) and vis[x][y]) msk |= (1<<d);
		}
		return (thr[msk] >= U[r][c]);
	};

	int cnt = 0;
	vector<pii> tmp;
	queue<pii> q;
	for(auto [sx, sy]: perm){
		owr[sx][sy] = true;
		if(U[sx][sy] == 0) continue;

		vis[sx][sy] = true;
		cnt = 1;
		tmp.pb(sx, sy);
		q.emplace(sx, sy);
		
		while(!q.empty()){
			auto [r, c] = q.front(); q.pop();
			for(int x, y, d = 0; d < 4; ++d){
				x = r + dx[d]; y = c + dy[d];
				if(!inside(x, y)) continue;
				if(U[x][y] == 0 or vis[x][y]) continue;
				if(!infect(x, y)) continue;
				if(owr[x][y]){ cnt = -1; break; }
				vis[x][y] = true;
				++cnt;
				tmp.pb(x, y);
				q.emplace(x, y);
			}
			if(cnt == -1) break;
		}

		for(auto [r, c]: tmp)
			vis[r][c] = false;
		tmp.clear();

		if(cnt == -1) continue;
		if(chmin(mnv, cnt)) mnc = 0;
		if(mnv == cnt) mnc += cnt;
	}

	cout << mnv << '\n';
	cout << mnc << '\n';
	return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 6 / 6
• Subtask 3: 80 / 80