Submission #1005968

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005968		makanhulia	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	12 ms	25328 KiB

mushrooms

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
typedef long long ll;
const ll INF = 1e9;
const ll MOD = 998244353;
const ll MAXN = 3e5 + 5;
const ll LOG = 30;
#define vll vector <ll>
#define pll pair <ll, ll>
#define fi first
#define se second
#define endl '\n'
#define lc (pos+1)
#define rc (pos+2*(mid-l+1))
#define mid ((l+r)/2)

ll n, m, d, s;
vector <string> a;
vector <vll> pf;

void solve(){
    cin >> n >> m >> d >> s;
    pf.resize(n+5);
    for(ll i = 0; i < n+5; i++){
        pf[i].resize(m+5);
    }
    a.resize(n+5);
    for(ll i = 1; i <= n; i++){
        string c; cin >> c;
        a[i] = '.' + c;
        for(ll j = 1; j <= m; j++){
            if(a[i][j] == 'S'){
                ll ai = max((ll)1, i-d), aj = max((ll)1, j-d), bi = min(n+1, i+d+1), bj = min(m+1, j+d+1);
                pf[ai][aj]++, pf[bi][bj]++;
                pf[ai][bj]--, pf[bi][aj]--;
            }
        }
    }
    ll ans = 0;
    for(ll i = 1; i <= n; i++){
        for(ll j = 1; j <= m; j++){
            pf[i][j] += pf[i-1][j] + pf[i][j-1] - pf[i-1][j-1];
            // cout << pf[i][j] << " ";
            if(a[i][j] == 'M'){
                ans += pf[i][j] >= s;
            }
        }
        // cout << endl;
    }
    cout << ans << endl;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // ll t; cin >> t;
    // while(t--){
        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