Submission #995106

#	Time	Username	Problem	Language	Result	Execution time	Memory
995106		vjudge1	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	13 ms	32932 KiB

mushrooms

#include <bits/stdc++.h>
using namespace std;
const int maxN = 5e5 + 10;
int n, m, k, d;
string s[maxN];
vector <int> pre[maxN];

int get(int u, int v, int i, int j){
    u = max(u, 1);
    v = max(v, 1);
    i = min(i, n);
    j = min(j, m);
    return pre[i][j] - pre[u - 1][j] - pre[i][v - 1] + pre[u - 1][v - 1];
}

void Init(){
    cin >> n >> m >> d >> k;
    pre[0].resize(m + 1);
    for (int i = 1; i <= n; ++i){
        cin >> s[i];
        s[i] = " " + s[i];
        pre[i].resize(m + 1, 0);
    }
    for (int i = 1; i <= n; ++i){
        for (int j = 1; j <= m; ++j){
            pre[i][j] = pre[i][j - 1] + pre[i - 1][j] - pre[i - 1][j - 1] + (s[i][j] == 'S');
        }
    }
    int ans = 0;
    for (int i = 1; i <= n; ++i){
        for (int j = 1; j <= m; ++j){
            if (s[i][j] != 'M') continue;
            int cnt = get(i - d, j - d, i + d, j + d);
            if (cnt >= k){
                ++ans;
            }
        }
    }
    cout << ans;

}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    Init();

}

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