Submission #252658

#	Time	Username	Problem	Language	Result	Execution time	Memory
252658		Mlxa	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	123 ms	158972 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define x first
#define y second
using namespace std;
using ll  = long long;
#define int ll

const int N = 3003;
int n, m;
char s[N][N];
int a[N][N];
int b[N][N];
int ans = 0;

signed main() {
#ifdef LC
    assert(freopen("input.txt", "r", stdin));
#endif
    ios::sync_with_stdio(0), cin.tie(0);
	cin >> n >> m;
	for (int i = 0; i < n; ++i) {
		cin >> s[i];
	}
	for (int i = n - 1; i >= 0; --i) {
		for (int j = m - 1; j >= 0; --j) {
			a[i][j] = a[i][j + 1] + (s[i][j] == 'O');
			b[i][j] = b[i + 1][j] + (s[i][j] == 'I');
			if (s[i][j] == 'J') {
				ans += a[i][j + 1] * b[i + 1][j];
			}
		}
	}
	cout << ans << "\n";
    return 0;
}

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