Submission #99549

#	Time	Username	Problem	Language	Result	Execution time	Memory
99549		Dat160601	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	284 ms	87544 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
#define fi first
#define se second

const int N = 3007;

int n, m, row[N][N], col[N][N];
long long ans = 0;
string s[N];

int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> n >> m;
	for(int i = 1; i <= n; i++){
		cin >> s[i];
		for(int j = 1; j <= m; j++){
			row[i][j] = row[i][j - 1];
			if(s[i][j - 1] == 'O') row[i][j]++;
			else if(s[i][j - 1] == 'I') col[j][i]++;
		}
	}
	for(int j = 1; j <= m; j++){
		for(int i = 1; i <= n; i++){
			col[j][i] += col[j][i - 1];
		}
	}
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			if(s[i][j - 1] != 'J') continue;
			ans += 1LL * (row[i][m] - row[i][j]) * (col[j][n] - col[j][i]);
		}
	}
	cout << ans;
}

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