Submission #139590

#	Time	Username	Problem	Language	Result	Execution time	Memory
139590		mlyean00	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	458 ms	160248 KiB

joi2019_ho_t1

#ifdef DEBUG
#include "debug.hpp"
#else
#pragma GCC optimize("Ofast")
#define trace(...)
#include <bits/stdc++.h>
#define endl '\n'
#endif

using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int h, w;
    cin >> h >> w;
    vector<string> grid(h);
    for (int i = 0; i < h; ++i) {
        cin >> grid[i];
    }

    vector<vector<ll>> row_o(h + 1, vector<ll>(w + 1));
    for (int i = 0; i < h; ++i) {
        for (int j = w - 1; j >= 0; --j) {
            row_o[i][j] = row_o[i][j + 1] + (grid[i][j] == 'O');
        }
    }
    vector<vector<ll>> col_i(h + 1, vector<ll>(w + 1));
    for (int j = 0; j < w; ++j) {
        for (int i = h - 1; i >= 0; --i) {
            col_i[i][j] = col_i[i + 1][j] + (grid[i][j] == 'I');
        }
    }

    ll ans = 0;
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            if (grid[i][j] != 'J') continue;
            ans += row_o[i][j] * col_i[i][j];
        }
    }

    cout << ans << endl;

    return 0;
}

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