Submission #754704

#	Time	Username	Problem	Language	Result	Execution time	Memory
754704		Unforgettablepl	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	22 ms	13128 KiB

mushrooms

/*
ID: samikgo1
TASK:
LANG: C++
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define f first
#define s second
//#define x first
//#define y second
const int INF = INT32_MAX;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
//    freopen("haybales.in","r",stdin);
//    freopen("haybales.out","w",stdout);
    ll r,c,d,k;
    cin >> r >> c >> d >> k;
    char grid[r+1][c+1];
    vector<vector<ll>> prefix(r+1,vector<ll>(c+1));
    for (int i = 1; i <= r; i++) {
        for (int j = 1; j <= c; j++) {
            prefix[i][j] = prefix[i-1][j] + prefix[i][j-1] - prefix[i-1][j-1];
            cin>>grid[i][j];
            if(grid[i][j]=='S')prefix[i][j]++;
        }
    }
    ll ans = 0;
    for (int i = 1; i <= r; i++) {
        for (int j = 1; j <= c; j++) {
            if(grid[i][j]!='M')continue;
            ll pre = prefix[min(i+d,r)][min(j+d,c)]+prefix[max(i-d-1,(ll)0)][max(j-d-1,(ll)0)] - prefix[max(i-d-1,(ll)0)][min(j+d,c)] - prefix[min(i+d,r)][max(j-d-1,(ll)0)];
            if(pre>=k)ans++;
        }
    }
    cout << ans;
}

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