Submission #1026486

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026486		overwatch9	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	342 ms	88840 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
    int n, m;
    cin >> n >> m;
    vector <string> grid(n+1);
    for (int i = 1; i <= n; i++) {
        cin >> grid[i];
        grid[i] = "0" + grid[i];
    }
    map <char, vector <vector <int>>> pfx;
    pfx['O'] = pfx['I'] = vector <vector <int>> (n+1, vector <int> (m+1));
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (grid[i][j] != 'J')
                pfx[grid[i][j]][i][j]++;
            pfx['O'][i][j] += pfx['O'][i][j-1];
            pfx['I'][i][j] += pfx['I'][i-1][j];
        }
    }
    ll ans = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (grid[i][j] != 'J')
                continue;
            ll a = pfx['O'][i][m] - pfx['O'][i][j];
            ll b = pfx['I'][n][j] - pfx['I'][i][j];
            ans += a * b;
        }
    }
    cout << ans << '\n';
}

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