Submission #1258749

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258749		vincent_nth	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	315 ms	150464 KiB

joi2019_ho_t1

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define str string
#define pii pair<long long, long long>
#define vll vector<ll>
#define endl '\n'

const ll mun = 3005, mod = 1e9 + 7;
ll n, m, k, q, ans = 0;
char a[mun][mun];
ll row[mun], col[mun], precol[mun][mun], prerow[mun][mun];

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cin >> n >> m;
    for (ll i = 0; i < mun; i++) {
        row[i] = 0;
        col[i] = 0;
    }
    for (ll i = 1; i <= n; i++) {
        for (ll j = 1; j <= m; j++) {
            cin >> a[i][j];
        }
    }
    for (ll i = 1; i <= n; i++) {
        for (ll j = 1; j <= m; j++) {
            if (a[i][j] == '0') row[i] = row[i] + 1;
            else if (a[i][j] == 'I') col[j] = col[j] + 1;
        }
    }
    for (ll j = 1; j <= m; j++) {
        for (ll i = 1; i <= n; i++) {
            precol[i][j] = precol[i - 1][j] + (a[i][j] == 'I');
        }
    }
    for (ll i = 1; i <= n; i++) {
        for (ll j = 1; j <= m; j++) {
            prerow[i][j] = prerow[i][j - 1] + (a[i][j] == 'O');
        }
    }
    for (ll i = 1; i <= n; i++) {
        for (ll j = 1; j <= m; j++) {
            if (a[i][j] == 'J') {
                ans += (prerow[i][m] - prerow[i][j]) * (precol[n][j] - precol[i][j]);
            }
        }
    }
    cout << ans;
}

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