Submission #140797

#	Time	Username	Problem	Language	Result	Execution time	Memory
140797		meatrow	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	485 ms	88652 KiB

joi2019_ho_t1

//#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;

const int N = 3005;

char a[N][N];
int row[N][N];
int col[N][N];

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

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