Submission #586480

#	Time	Username	Problem	Language	Result	Execution time	Memory
586480		M_W	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	13 ms	8516 KiB

mushrooms

#include <bits/stdc++.h>
#define ii pair<int, int>
using namespace std;
vector<vector<int>> v;
int ans = 0;
queue<ii> q;
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	int N, M, D, K;
	cin >> N >> M >> D >> K;
	int rd = D * 2 + 1;
	for(int i = 0; i < N; i++){
		string line;
		cin >> line;
		vector<int> tmp;
		for(int j = 0; j < M; j++){
			int qsl = j == 0 ? 0 : tmp[j - 1];
			int qsu = i == 0 ? 0 : v[i - 1][j];
			int qslu = (i == 0 || j == 0) ? 0 : v[i - 1][j - 1];
			
			tmp.push_back(qsl + qsu - qslu + (line[j] == 'S' ? 1 : 0));
			if(line[j] == 'M') q.push({i + D, j + D});
		}
		v.push_back(tmp);
	}
	while(!q.empty()){
		auto [ni, nj] = q.front();
		int mi = min(ni, N - 1), mj = min(nj, M - 1);
		
		int qsu2 = ni - rd < 0 ? 0 : v[ni - rd][mj]; 
		int qsl2 = nj - rd < 0 ? 0 : v[mi][nj - rd];
		int qslu2 = (ni - rd < 0 || nj - rd < 0) ? 0 : v[ni - rd][nj - rd];
		
		if(v[mi][mj] - qsl2 - qsu2 + qslu2 >= K) ans++;
		q.pop();
	}
	cout << ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 18 / 18
• Subtask 4: 23 / 23
• Subtask 5: 19 / 19
• Subtask 6: 21 / 21