Submission #754670

#	Time	Username	Problem	Language	Result	Execution time	Memory
754670		KN200711	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	338 ms	88420 KiB

joi2019_ho_t1

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

char arr[3002][3002];
int O[3002][3002], I[3002][3002];

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int N, M;
	cin>>N>>M;
	for(int i=1;i<=N;i++) {
		for(int k=1;k<=M;k++) {
			cin>>arr[i][k];
		}
	}
	for(int i=1;i<=N;i++) {
		for(int k=M;k>=1;k--) {
			O[i][k] = O[i][k + 1];
			if(arr[i][k] == 'O') O[i][k]++;
		}
	}
	
	for(int i=1;i<=M;i++) {
		for(int k=N;k>=1;k--) {
			I[k][i] = I[k+1][i];
			if(arr[k][i] == 'I') I[k][i]++;
		}
	}
	
	ll ans = 0ll;
	for(int i=1;i<=N;i++) {
		for(int k=1;k<=M;k++) {
			if(arr[i][k] != 'J') continue;
			ans += 1ll * O[i][k] * 1ll * I[i][k];
		//	cout<<i<<" "<<k<<" "<<O[i][k]<<" "<<I[i][k]<<endl;
		}
	}
	
	cout<<ans<<endl;
	return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50