Submission #1075275

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075275		quangminh412	Bitaro the Brave (JOI19_ho_t1)	C++14	100 / 100	140 ms	88680 KiB

joi2019_ho_t1

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

/*
  John Watson
  https://codeforces.com/profile/quangminh98

  Mua Code nhu mua Florentino !!
*/

#define faster() ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define ll long long

const int maxn = 3009;

int preO[maxn][maxn], preI[maxn][maxn];
char a[maxn][maxn];
int H, W;

signed main()
{
	if (fopen("test.inp", "r"))
	{
		freopen("test.inp", "r", stdin);
		freopen("test.out", "w", stdout);
	}
	faster();

	cin >> H >> W;
	for (int i = 1; i <= H; i++)
		for (int j = 1; j <= W; j++)
		{
			cin >> a[i][j];
			
			preO[i][j] = preO[i][j - 1] + (a[i][j] == 'O');
			preI[i][j] = preI[i - 1][j] + (a[i][j] == 'I');  
		}

	ll res = 0;
	for (int i = 1; i <= H; i++)
		for (int j = 1; j <= W; j++)
			if (a[i][j] == 'J')
				res += (preO[i][W] - preO[i][j]) * (preI[H][j] - preI[i][j]);

	cout << res << '\n';

	return 0;
}

Compilation message (stderr)

joi2019_ho_t1.cpp: In function 'int main()':
joi2019_ho_t1.cpp:24:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |   freopen("test.inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
joi2019_ho_t1.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   freopen("test.out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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