Submission #1063810

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063810		Luvidi	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	13 ms	8284 KiB

mushrooms

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

#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fs first
#define sc second
#define pb push_back

void solve() {
    int n,m,d,k;
    cin>>n>>m>>d>>k;
    int a[n+1][m+1];
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            char c;
            cin>>c;
            if(c=='.')a[i][j]=0;
            else if(c=='M')a[i][j]=1;
            else a[i][j]=2;
        }
    }
    int pre[n+1][m+1];
    memset(pre,0,sizeof(pre));
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(a[i][j]==2){
                pre[max(1,i-d)][max(1,j-d)]++;
                if(i+d+1<=n)pre[i+d+1][max(1,j-d)]--;
                if(j+d+1<=m)pre[max(1,i-d)][j+d+1]--;
                if(i+d+1<=n&&j+d+1<=m)pre[i+d+1][j+d+1]++;
            }
        }
    }
    int ans=0;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            pre[i][j]+=pre[i-1][j]+pre[i][j-1]-pre[i-1][j-1];
            ans+=a[i][j]==1&&pre[i][j]>=k;
        }
    }
    cout<<ans;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    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