Submission #546929

#	Time	Username	Problem	Language	Result	Execution time	Memory
546929		Ahmed57	Collecting Mushrooms (NOI18_collectmushrooms)	C++14	100 / 100	24 ms	26736 KiB

mushrooms

#include <bits/stdc++.h>

using namespace std;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n,m,d,k;
	cin>>n>>m>>d>>k;
	char arr[n+5][m+5];
	int pre[n+5][m+5];
    int fores[n+5][m+5];
    memset(pre,0,sizeof pre);
    memset(fores,0,sizeof fores);
	for(int i=1;i<=n;i++) {
		for(int j=1;j<=m;j++) {
			char a;
			cin>>a;
			arr[i][j] = a;
			if(a=='S'){
                fores[i][j]++;
			}
		}
	}
	pre[1][1] = fores[1][1];
	for(int i = 2;i<=m;i++)
        pre[1][i]=pre[1][i-1]+fores[1][i];
    for(int i = 2;i<=n;i++)
        pre[i][1]=pre[i-1][1]+fores[i][1];
    for(int i=2;i<=n;i++){
        for(int j=2;j<=m;j++){
            pre[i][j]=pre[i-1][j]+pre[i][j-1]-pre[i-1][j-1]+fores[i][j];
        }
    }
	int ans=0;
	for(int i = 1;i<=n;i++){
        for(int j = 1;j<=m;j++){
            if(arr[i][j]=='M'){
            long long x1 = max(i-d,1) , y1 = max(j-d,1) , x2 = min(i+d,n) , y2 = min(j+d,m);
            long long sum = pre[x2][y2];
            if(x1>1)sum-=pre[x1-1][y2];
            if(y1>1)sum-=pre[x2][y1-1];
            if(x1>1&&y1>1)sum+=pre[x1-1][y1-1];
            if(sum>=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