Submission #1266313

#	Time	Username	Problem	Language	Result	Execution time	Memory
1266313		g4yuhg	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	321 ms	150412 KiB

joi2019_ho_t1

//Huyduocdithitp
#include <bits/stdc++.h>
typedef long long ll;
#define pii pair<ll, ll> 
#define MP make_pair
#define fi first
#define se second
#define TASK "connect"
#define faster ios_base::sync_with_stdio(false);cin.tie(NULL);
#define N 3005
#define LOG 18
#define endl '\n'
using namespace std;

ll h, w;
char a[N][N];

ll pf1[N][N];
ll pf2[N][N];

signed main(void) {
	faster;
	
	cin >> h >> w;
	for (int i = 1; i <= h; i ++) {
		for (int j = 1; j <= w; j ++) {
			cin >> a[i][j];
		}
	}
	
	for (int i = 1; i <= h; i ++) {
		for (int j = w; j >= 1; j --) {
			pf1[i][j] = pf1[i][j + 1];
			if (a[i][j] == 'O') pf1[i][j] ++ ;
		}
	}
	
	for (int j = 1; j <= w; j ++) {
		for (int i = h; i >= 1; i --) {
			pf2[i][j] = pf2[i + 1][j];
			if (a[i][j] == 'I') pf2[i][j] ++ ;
		}
	}
	
	ll ans = 0;
	
	for (int i = 1; i <= h; i ++) {
		for (int j = 1; j <= w; j ++) {
			if (a[i][j] == 'J') {
				ans += pf1[i][j] * pf2[i][j];
			}
		}
	}
	
	cout << ans;
	
	
	return 0;
}

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