Submission #1180250

#	Time	Username	Problem	Language	Result	Execution time	Memory
1180250		miniob	Bitaro the Brave (JOI19_ho_t1)	C++20	100 / 100	338 ms	82456 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using namespace std;

string tab[3007];
int prefk[3007][3007];
int prefw[3007][3007];

int main() 
{
	int h, w;
	cin >> h >> w;
	for(int i = 1; i <= h; i++)
	{
		cin >> tab[i];
	}
	for(int i = h; i >= 1; i--)
	{
		for(int j = w - 1; j >= 0; j--)
		{
			prefw[i][j + 1] = prefw[i][j + 2];
			if(tab[i][j] == 'O')
			{
				prefw[i][j + 1]++;
			}
		}
	}
	for(int j = w - 1; j >= 0; j--)
	{
		for(int i = h; i >= 1; i--)
		{
			prefk[i][j + 1] = prefk[i + 1][j + 1];
			if(tab[i][j] == 'I')
			{
				prefk[i][j + 1]++;
			}
		}
	}
	/*for(int i = 1; i <= h; i++)
	{
		for(int j = 1; j <= w; j++)
		{
			cout << prefk[i][j] << " ";
		}
		cout << endl;
	}
	cout << endl;
	for(int i = 1; i <= h; i++)
	{
		for(int j = 1; j <= w; j++)
		{
			cout << prefw[i][j] << " ";
		}
		cout << endl;
	}*/
	long long ans = 0;
	for(int i = 1; i <= h; i++)
	{
		for(int j = 0; j < w; j++)
		{
			if(tab[i][j] == 'J')
			{
				ans += prefk[i][j + 1] * prefw[i][j + 1];
			}
		}
	}
	cout << ans << endl;
	return 0;
}

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