Submission #1027176

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027176		vjudge1	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	254 ms	150624 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#define ll long long
#define nikah ios_base::sync_with_stdio(0); cin.tie(0);
const ll maxn = 3e3+7;
using namespace std;

ll t,n,m;
char a[maxn][maxn];
ll pref1[maxn][maxn], pref2[maxn][maxn];

int main () {
	nikah
	cin>>n>>m;
	for (ll i=1; i<=n; i++) {
		for (ll j=1; j<=m; j++) {
			cin>>a[i][j];
		}
	}
	ll ans = 0;
	for (ll i=1; i<=n; i++) {
		for (ll j=m; j>=1; j--) {
			if (a[i][j] == 'O') pref1[i][j]++;
			pref1[i][j] += pref1[i][j+1];
		}
	}
	for (ll j=1; j<=m; j++) {
		for (ll i=n; i>=1; i--) {
			if (a[i][j] == 'I') pref2[i][j]++;
			pref2[i][j] += pref2[i+1][j];
		}
	}
	for (ll i=1; i<=n; i++) {
		for (ll j=1; j<=m; j++) {
			if (a[i][j] == 'J') {
				ans += (pref1[i][j] * pref2[i][j]);
			}
		}
	}
	cout<<ans<<endl;
}

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