Submission #970854

#	Time	Username	Problem	Language	Result	Execution time	Memory
970854		MercubytheFirst	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	263 ms	160084 KiB

joi2019_ho_t1

#include <bits/stdc++.h>
using ll = long long;
#define pb push_back



// overflow check strat : a * b / b == a
using std::cin;
using std::cout;

template <typename T> 
std::ostream& operator<<( std::ostream& os, const std::vector<T>& v );
using namespace std;
const ll inf = 1e9 + 37;


void solve(){
  ll n, m;
  cin >> n >> m;
  vector<string> g(n);
  for(auto& s : g)
    cin >> s;
  vector<vector<ll> > osuf(n + 1, vector<ll>(m + 1)), isuf(n + 1, vector<ll>(m + 1));
  for(ll row = 0; row < n; ++row) {
    for(ll col = m - 1; col >= 0; --col) {
      osuf[row][col] = osuf[row][col + 1] + (g[row][col] == 'O');
    }
  }
  for(ll col = 0; col < m; ++col) {
    for(ll row = n - 1; row >= 0; --row) {
      isuf[row][col] = isuf[row + 1][col] + (g[row][col] == 'I');
    }
  }
  ll ans = 0;
  for(ll i = 0; i < n; ++i) {
    for(ll j = 0; j < m; ++j) {
      if(g[i][j] != 'J')
        continue;
      ans += osuf[i][j] * isuf[i][j];
    }
  }
  cout << ans << endl;
}   

signed main() {
  #ifdef LOCAL
  freopen("test.in", "r", stdin);
  freopen("test.out", "w", stdout);
  #endif
  std::ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  // signed t = 0; cin >> t; while(t--)
    solve();
}

template <typename T> 
std::ostream& operator<<( std::ostream& os, const std::vector<T>& v ) {
  os << "[";
  for (auto x : v)
    os << x << ", ";
  os << "]\n";
  return os;
}

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