Submission #1269525

#	Time	Username	Problem	Language	Result	Execution time	Memory
1269525		ducdev	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	16 ms	16988 KiB

mushrooms

// Author: 4uckd3v - Nguyen Cao Duc
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int MAX_N = 1e6;
const int MOD = 1e9 + 7;

int m, n, d, k;
vector<vector<char>> a;
vector<vector<int>> pref;

void updateRange(int i, int j) {
    int x = max(1, i - d), y = max(1, j - d);
    int u = min(m, i + d), v = min(n, j + d);

    pref[x][y]++, pref[u + 1][v + 1]++;
    pref[u + 1][y]--, pref[x][v + 1]--;
};

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (fopen("MAIN.INP", "r")) {
        freopen("MAIN.INP", "r", stdin);
        freopen("MAIN.OUT", "w", stdout);
    };

    cin >> m >> n >> d >> k;
    a.resize(m + 5, vector<char>(n + 5));
    pref.resize(m + 5, vector<int>(n + 5, 0));

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            cin >> a[i][j];

            if (a[i][j] == 'S') updateRange(i, j);
        };
    };

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            pref[i][j] += pref[i - 1][j] + pref[i][j - 1] - pref[i - 1][j - 1];
        };
    };

    int res = 0;
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (a[i][j] == 'M' && pref[i][j] >= k) res++;
        };
    };
    cout << res << '\n';
};

Compilation message (stderr)

mushrooms.cpp: In function 'int main()':
mushrooms.cpp:26:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |         freopen("MAIN.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mushrooms.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen("MAIN.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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