Submission #922101

#	Time	Username	Problem	Language	Result	Execution time	Memory
922101		406	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	115 ms	163040 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
#define int int64_t
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)

using namespace std;
using ar = array<int, 2>;

const int64_t INF = 1ll << 60;
const int N = 3000 + 50;
string s[N];
int n, m, cntI[N][N], cntO[N][N];

signed main() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr); 
        cin >> n >> m;
        FOR(i, 0, n) cin >> s[i];
        int ans = 0;
        for (int i = n - 1; i >= 0; --i) {
                for (int j = m - 1; j >= 0; --j) {
                        cntI[i][j] = cntI[i][j + 1] + (s[i][j] == 'O');
                        cntO[i][j] = cntO[i + 1][j] + (s[i][j] == 'I');
                        ans += (s[i][j] == 'J' ? cntI[i][j] * cntO[i][j] : 0);
                }
        }
        cout << ans << '\n';
        return 0;
}

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