Submission #331523

#	Time	Username	Problem	Language	Result	Execution time	Memory
331523		limabeans	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	148 ms	89452 KiB

joi2019_ho_t1

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

template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl





using ll = long long;


const int maxn = 3001;



int n, m;
string g[maxn];
int O[maxn][maxn];
int I[maxn][maxn];

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);  cout.tie(0);

    cin>>n>>m;
    for (int i=0; i<n; i++) {
	cin>>g[i];
    }

    for (int i=0; i<n; i++) {
	for (int j=m-1; j>=0; j--) {
	    O[i][j]=(g[i][j]=='O')+O[i][j+1];
	}
    }

    for (int i=n-1; i>=0; i--) {
	for (int j=0; j<m; j++) {
	    I[i][j]=(g[i][j]=='I')+I[i+1][j];
	}
    }

    ll res = 0;

    for (int i=0; i<n; i++) {
	for (int j=0; j<m; j++) {
	    if (g[i][j]=='J') {
		res += 1ll*O[i][j+1]*I[i+1][j];
	    }
	}
    }

    cout<<res<<endl;
    
    return 0;
}

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