Submission #863951

#	Time	Username	Problem	Language	Result	Execution time	Memory
863951		Arthas	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	130 ms	54352 KiB

joi2019_ho_t1

/// I'm only brave when I have to be
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define fast_io ios::sync_with_stdio(false);cin.tie(NULL);
#define file_io freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define FOR(i,k,n) for(int i = k; i < n; ++ i)
#define debf cout<<"(0-0)\n";
#define all(x) x.begin(), x.end()
#define dec(x) cout << fixed << setprecision(x);
#define pf push_front
#define ppf pop_front
#define dash " ------- "
#define what(x) cerr << #x << " is " << x << endl;
#define eb emplace_back
//#define int short int
//#define int long long
#define sz(s) (int) (s.size())
#define fl cout.flush()

using namespace std;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;
typedef unsigned long long ull;
typedef long double ld;

template <class T> using max_heap = priority_queue <T, vector <T>, less <T> >;
template <class T> using min_heap = priority_queue <T, vector <T>, greater <T> >;

constexpr int MOD = 1e9 + 7, N = 3008, M = 1e5 + 8, SQ = 500, INF = 2e9 + 8, LGN = 11, mod = 998244353;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, m, cnt1[N][N];
ll ans;
string s[N];

int32_t main(){
  fast_io;
  cin >> n >> m;
  FOR (i, 0, n){
    cin >> s[i];
  }
  for (int i = 0; i < n; ++ i){
    for (int j = m - 1; j >= 0; -- j){
      cnt1[i][j] = cnt1[i][j+1] + (s[i][j] == 'O');
    }
  }
  int x = 0;
  for (int j = 0; j < m; ++ j){
    for (int i = n - 1; i >= 0; -- i){
      x += s[i][j] == 'I';
      if (s[i][j] == 'J'){
        ans += 1LL * cnt1[i][j] * x;
      }
    }
    x = 0;
  }
  cout << ans;
  return 0;
}

// Yesterday is history
// Tomorrow is a mystery
// but today is a gift
// That is why it is called the present

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