Submission #507615

#	Time	Username	Problem	Language	Result	Execution time	Memory
507615		thomas_li	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	651 ms	88484 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using namespace std;
const int MM = 3e3+5;
int n,m,psar[MM][MM],psac[MM][MM]; char g[MM][MM];
int main(){
	cin >> n >> m;	
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			cin >> g[i][j];
		}
	}
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			psar[i][j] = psar[i][j-1] + (g[i][j] == 'O');
		}
	}
	for(int j = 1; j <= m; j++){
		for(int i = 1; i <= n; i++){
			psac[i][j] = psac[i-1][j] + (g[i][j] == 'I');
		}
	}
	int64_t ans = 0;
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= m; j++){
			if(g[i][j] == 'J'){
				int cnt1 = psar[i][m] - psar[i][j];
				int cnt2 = psac[n][j] - psac[i][j];
				ans += 1ll*cnt1*cnt2;
			}
		}
	}
	cout << ans << "\n";
}

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