Submission #679327

#	Time	Username	Problem	Language	Result	Execution time	Memory
679327		kusssso	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	362 ms	88484 KiB

joi2019_ho_t1

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 3005;

int n, m;
char a[N][N];
int d[2][N][N];

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    
    cin >> n >> m;
    for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
        cin >> a[i][j];
        if (a[i][j] == 'O') d[0][i][j]++;
        if (a[i][j] == 'I') d[1][i][j]++;
    }
    for (int i = 1; i <= n; i++) for (int j = m; j >= 1; j--) d[0][i][j] += d[0][i][j + 1];
    for (int j = 1; j <= m; j++) for (int i = n; i >= 1; i--) d[1][i][j] += d[1][i + 1][j];
    ll ans = 0;
    for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
        if (a[i][j] == 'J')
            ans += 1LL * d[0][i][j] * d[1][i][j];
    }
    cout << ans;
    
    return 0;
}

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