Submission #926473

#	Time	Username	Problem	Language	Result	Execution time	Memory
926473		shmad	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	10 ms	5836 KiB

mushrooms

#pragma GCC optimize("O3", "unroll-loops") // "Ofast" 	
#pragma GCC target("avx2", "bmi", "bmi2", "lzcnt", "popcnt") 

#include <bits/stdc++.h>

//#define int long long
#define vt vector
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define f first
#define s second
#define dbg(x) cerr << #x << " = " << x << '\n'
#define bit(x, i) ((x) >> (i) & 1)

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int, int>;

const int N = 1e6 + 5, mod = 1e9 + 7;
const ll inf = 1e18 + 7;
const ld eps = 1e-6;

ll add (ll a, ll b) {
	a += b;
	if (a < 0) a += mod;
	if (a >= mod) a -= mod;
	return a;
}

ll mul (ll a, ll b) {
	a *= b;
	if (a >= mod) a %= mod;
	return a;
}

int n, m, d, k;

void solve () {
	cin >> n >> m >> d >> k;
	char a[n + 1][m + 1];
	int p[n + 1][m + 1];
	p[0][0] = p[0][1] = p[1][0] = 0;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) cin >> a[i][j], p[i][j] = p[i - 1][j] + p[i][j - 1] - p[i - 1][j - 1] + (a[i][j] == 'S');
	}
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= m; j++) {
			if (a[i][j] == 'M') {
				int x1 = max(1, i - d), y1 = max(1, j - d), x2 = min(n, i + d), y2 = min(m, j + d);
				if (p[x2][y2] - p[x2][y1 - 1] - p[x1 - 1][y2] + p[x1 - 1][y1 - 1] >= k) ans++;
			}
		}
	}
	cout << ans;
	cout << '\n';
}

bool testcases = 0;

signed main() {
	cin.tie(0) -> sync_with_stdio(0);
	int test = 1;
	if (testcases) cin >> test;
	for (int cs = 1; cs <= test; cs++) {
		solve();
	}
}

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