Submission #925577

#	Time	Username	Problem	Language	Result	Execution time	Memory
925577		vjudge1	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	26 ms	20056 KiB

mushrooms

//Bismillahir-Rahmanir-Rahim

#include <bits/stdc++.h>
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,sse4.1,sse4.2,popcnt,avx,avx2")

#define pb push_back
#define pii pair <int, int>
#define pll pair <long long, long long>
#define pld pair <long double, long double>
#define ll long long
#define ld long double
#define x first
#define y second
#define all(v) v.begin(),v.end()
#define sz(s) (int)s.size()
#define skip continue
#define bpop(x) (ll)__builtin_popcountll(x)

using namespace std;

const int N = 5e5 + 7;
const int M = 1e3 + 7;
const int maxA = 2e6 + 7;
const int inf = 1e9 + 7;
const ll INF = 2e18 + 7;
const int MOD = 1e9 + 7;
const ld eps = 1e-9;

pii dir[] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

//#define int long long

int n, m, k, d;
void solve() {
    cin >> n >> m >> d >> k;
    char a[n + 7][m + 7];
    int pre[n + 7][m + 7];
    memset(a, 0, sizeof a);
    memset(pre, 0, sizeof pre);
    for (int i = 1;i <= n;i++) {
        for (int j = 1;j <= m;j++) {
            cin >> a[i][j];
            if (a[i][j] == 'S') {
                int x1 = max(1, i - d), y1 = max(1, j - d);
                int x2 = min(n, i + d), y2 = min(m, j + d);
                pre[x1][y1]++, pre[x1][y2 + 1]--, pre[x2 + 1][y1]--, pre[x2 + 1][y2 + 1]++;
            }
        }
    }
    for (int i = 1;i <= n;i++) {
        for (int j = 1;j <= m;j++)pre[i][j] += pre[i][j - 1];
    }
    for (int j = 1;j <= m;j++) {
        for (int i = 1;i <= n;i++)pre[i][j] += pre[i - 1][j];
    }
    int ans = 0;
    for (int i = 1;i <= n;i++) {
        for (int j = 1;j <= m;j++) {
            if (a[i][j] == 'M')ans += pre[i][j] >= k;
        }
    }
    cout << ans;
}
signed main() {
    //srand(time(NULL));
    ios_base::sync_with_stdio(0);
    cout.tie(0);
    //freopen("tests.in", "r", stdin);
    //freopen("milkorder.out", "w", stdout);
    int test = 1;
    //cin >> test;
    for (int t = 1;t <= test;t++) {
        //cout << "Case " << t << ": ";
        solve();
    }
    return 0;
}

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