Submission #965239

#	Time	Username	Problem	Language	Result	Execution time	Memory
965239		thinknoexit	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	97 ms	89656 KiB

joi2019_ho_t1

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 3030;
char c[N][N];
int qs[2][N][N];
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    for (int i = 1;i <= n;i++) {
        cin >> (c[i] + 1);
        for (int j = 1;j <= m;j++) {
            qs[0][i][j] = qs[0][i][j - 1] + (c[i][j] == 'O');
            qs[1][i][j] = qs[1][i - 1][j] + (c[i][j] == 'I');
        }
    }
    ll ans = 0;
    for (int i = 1;i < n;i++) {
        for (int j = 1;j < m;j++) {
            if (c[i][j] == 'J') {
                ans += 1ll * (qs[0][i][m] - qs[0][i][j]) * (qs[1][n][j] - qs[1][i][j]);
            }
        }
    }
    cout << ans;
    return 0;
}

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