Submission #818771

#	Time	Username	Problem	Language	Result	Execution time	Memory
818771		Zanite	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	299 ms	80236 KiB

joi2019_ho_t1

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

const int maxN	= 3023;

int H, W;
char grid[maxN][maxN];
int O[maxN][maxN], I[maxN][maxN];

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL);

	cin >> H >> W;
	for (int i = 1; i <= H; i++) {
		for (int j = 1; j <= W; j++) {
			cin >> grid[i][j];
		}
	}

	for (int i = 1; i <= H; i++) {
		for (int j = W; j >= 1; j--) {
			O[i][j] = O[i][j+1] + (grid[i][j] == 'O');
		}
	}

	for (int j = 1; j <= W; j++) {
		for (int i = H; i >= 1; i--) {
			I[i][j] = I[i+1][j] + (grid[i][j] == 'I');
		}
	}

	long long ans = 0;
	for (int i = 1; i <= H; i++) {
		for (int j = 1; j <= W; j++) {
			if (grid[i][j] == 'J') {
				ans += 1ll * O[i][j] * I[i][j];
			}
		}
	}
	cout << ans << '\n';
}

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