Submission #1133965

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133965		vibeduck	Collecting Mushrooms (NOI18_collectmushrooms)	C++20	100 / 100	21 ms	23272 KiB

mushrooms

#include <bits/stdc++.h> 
using namespace std;

#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define int long long
#define all(x) (x).begin(), (x).end()

typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<bool>> vvb;
typedef vector<vector<ll>> vvll;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<char> vc;
typedef vector<vector<char>> vvc;
typedef map<int, int> mii;
typedef unordered_map<int, int> umii;

const int mod = 1e9 + 7;
const int inf = INTMAX_MAX;
const bool tc = false;

int sum(int x1, int x2, int y1, int y2, vvi &pfix) {
    x1 = max(x1, (int)0); y1 = max(y1, (int)0);
    x2 = min(x2, (int)pfix.size()-2); y2 = min(y2, (int)pfix[0].size()-2);
    x2++; y2++;
    //cout << x1 << " " << y1 << " " << x2 << " " << y2 << " query\n"; 
    return pfix[x2][y2] - pfix[x2][y1] - pfix[x1][y2] + pfix[x1][y1];
    //return 0;
}

inline void solve() {
    int r, c, d, k;
    cin >> r >> c >> d >> k;
    vector<pii> ms;
    vvi grid(r, vi(c, 0)); for (int i = 0; i < r; i++) for (int j = 0; j < c; j++) {
        char x; cin >> x;
        if (x == '.') continue;
        if (x == 'S') grid[i][j] = 1;
        if (x == 'M') ms.pb({i, j});
    }
    vvi pfix(r + 1, vi(c + 1)); for (int i = 1; i <= r; i++) for (int j = 1; j <= c; j++) pfix[i][j] = pfix[i - 1][j] + pfix[i][j - 1] - pfix[i - 1][j - 1] + grid[i - 1][j - 1];
    int ans = 0;
    for (auto &x : ms) {
        ans += (sum(x.fi - d, x.fi + d, x.se - d, x.se + d, pfix) >= k);
    }
    cout << ans << '\n';
    //cout << "h\n";
}

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

signed main() {
    ios::sync_with_stdio(false);
    cout.tie(0);
    cin.tie(0);
    //setIO();

    int t = 1;
    if (tc) {
        cin >> t;
    }

    while (t--) {
        solve();
    }
}

Compilation message (stderr)

mushrooms.cpp: In function 'void setIO(std::string)':
mushrooms.cpp:62:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mushrooms.cpp:63:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |     freopen((s + ".out").c_str(), "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