Submission #985667

#	Time	Username	Problem	Language	Result	Execution time	Memory
985667		vyshniak_n	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	156 ms	159896 KiB

joi2019_ho_t1

//#pragma optimize("Ofast")
//#pragma optimize("unroll-loops")
//#pragma traget("avx,avx2")

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <cstdint>
#include <cstring>
#include <string>
#include <cstdlib>
#include <vector>
#include <bitset>
#include <map>
#include <queue>
#include <ctime>
#include <stack>
#include <set>
#include <list>
#include <random>
#include <deque>
#include <functional>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <complex>
#include <numeric>
#include <cassert>
#include <array>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <thread>

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define el '\n'
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define point pair <ll, ll>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

using namespace std;

#include <random>
mt19937 rnd(time(0));

const ll INF = 1e18 + 10;
const ll inf = 1e9 + 10;
const ll N = 3e3 + 10;
const ll mod = 1e9 + 7;
const ll K = 200;
const ll LOG = 8;

char a[N][N];
ll pref[N][N][2];

void solve() {
    ll h, w;
    cin >> h >> w;

    for (ll i = 1; i <= h; i++)
        for (ll j = 1; j <= w; j++)
            cin >> a[i][j];

    for (ll i = 1; i <= h; i++)
        for (ll j = 1; j <= w; j++)
            pref[i][j][0] = pref[i][j - 1][0] + (a[i][j] == 'O');
    for (ll i = 1; i <= h; i++)
        for (ll j = 1; j <= w; j++)
            pref[i][j][1] = pref[i - 1][j][1] + (a[i][j] == 'I');

    ll ans = 0;
    for (ll i = 1; i <= h; i++) {
        for (ll j = 1; j <= w; j++) {
            if (a[i][j] != 'J')
                continue;

            ans += (pref[i][w][0] - pref[i][j][0]) * (pref[h][j][1] - pref[i][j][1]);
        }
    }

    cout << ans << el;
    return;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int tests = 1;
    //cin >> tests;

    while (tests--) 
        solve();
    return 0;
}
/*
*/

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