Submission #256351

#	Time	Username	Problem	Language	Result	Execution time	Memory
256351		Osama_Alkhodairy	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	294 ms	89336 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long

const int N = 3001;

int n, m, g[N][N], h[N][N];
vector <string> a;

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

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