Submission #1313422

#	Time	Username	Problem	Language	Result	Execution time	Memory
1313422		shirokito	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	136 ms	80328 KiB

joi2019_ho_t1

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

#define all(a) (a).begin(), (a).end()

using ll = long long;

const int N = 3000 + 24;

int n, m, O[N][N], I[N][N];
char a[N][N];

void solve() {
    cin >> n >> m;

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
        }
    }

    for (int i = n; i >= 1; i--) {
        for (int j = m; j >= 1; j--) {
            O[i][j] = O[i][j + 1] + (a[i][j] == 'O');
            I[i][j] = I[i + 1][j] + (a[i][j] == 'I');
        }
    }

    ll res = 0;

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (a[i][j] == 'J') {
                res += 1LL * O[i][j] * I[i][j];
            }
        }
    }

    cout << res << '\n';
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);

    int T = 1; // cin >> T;
    while (T--) {
        solve();
    }
}

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