Submission #1223036

#	Time	Username	Problem	Language	Result	Execution time	Memory
1223036		ffeyyaae_	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	223 ms	80836 KiB

joi2019_ho_t1

#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int N = 3005;

int n, m;
string arr[N];
int qsO[N][N], qsI[N][N];

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

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