Submission #1279969

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279969		dhuyyyy	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	144 ms	79832 KiB

joi2019_ho_t1

#include<bits/stdc++.h>
#define fi first
#define se second
#define int long long
using namespace std;

using ll = long long;
using ii = pair<int, int>;
using aa = array<int,3>;

const int N = 3005;

int n, m, cur, ans = 0;

int pre[N][N];

char a[N][N];

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

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