Submission #679370

#	Time	Username	Problem	Language	Result	Execution time	Memory
679370		Duy_e	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	234 ms	150636 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#define ll long long
#define pii pair <ll, ll>
#define st first
#define nd second
#define rep(i, n, m) for (ll i = (n); i <= (m); i ++)
#define rrep(i, m, n) for (ll i = (m); i >= (n); i --)

using namespace std;
const long long N = 3000 + 5;

ll n, m, f[N][N], g[N][N];
char a[N][N];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n >> m;
    rep(i, 1, n) rep(j, 1, m)
        cin >> a[i][j];

    rep(i, 1, n) {
        rep(j, 1, m) {
            f[i][j] = f[i][j - 1] + (a[i][j] == 'O');
            g[i][j] = g[i - 1][j] + (a[i][j] == 'I');
        }
    }

    ll ans = 0;
    rep(i, 1, n) rep(j, 1, m) if (a[i][j] == 'J') {
        ll cntO = f[i][m] - f[i][j];
        ll cntI = g[n][j] - g[i][j];
        ans += cntO * cntI;
    }

    cout << ans;
    return 0;
}

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