結果

問題 No.1470 Mex Sum
コンテスト
ユーザー ninoinui
提出日時 2021-04-09 21:29:50
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 43 ms / 2,000 ms
コード長 3,799 bytes
コンパイル時間 2,023 ms
コンパイル使用メモリ 202,956 KB
最終ジャッジ日時 2025-01-20 13:36:45
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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ファイルパターン 結果
sample AC * 2
other AC * 49
権限があれば一括ダウンロードができます

ソースコード

diff # 

#ifndef _DEBUG
#define _DEBUG
#include __FILE__

signed main() {
  long N;
  cin >> N;
  vector<long> A(N);
  for (long i = 0; i < N; i++) cin >> A.at(i);

  map<long, long> MA;
  for (const auto& a : A) MA[a]++;

  long ans = 0;
  for (long i = 0; i < N; i++) {
    if (A.at(i) == 1) {
      long tmp = MA[2];
      ans += tmp * 3;
      ans += (N - tmp - 1) * 2;
    } else if (A.at(i) == 2) {
      long tmp = MA[1];
      ans += tmp * 3;
      ans += (N - tmp - 1);
    } else {
      long tmp = MA[1];
      ans += tmp * 2;
      ans += (N - tmp - 1);
    }
  }
  cout << ans / 2 << "\n";
}

#else
// #undef _DEBUG
#pragma GCC diagnostic warning "-Wextra"
#pragma GCC diagnostic warning "-Wshadow"
#include <bits/stdc++.h>
using namespace std;

struct io_setup {
  io_setup() { cin.tie(nullptr)->sync_with_stdio(false); }
} io_setup;

template <class A, class B> bool cmin(A& a, const B& b) {
  if (a > b) return a = b, true;
  return false;
}

template <class A, class B> bool cmax(A& a, const B& b) {
  if (a < b) return a = b, true;
  return false;
}

template <class A, class B> ostream& operator<<(ostream& os, const pair<A, B>& p);

template <class A, class B, class C> ostream& operator<<(ostream& os, const tuple<A, B, C>& t);

template <class A, class B, class C, class D> ostream& operator<<(ostream& os, const tuple<A, B, C, D>& t);

#define foreach(it, a) for (auto it = a.begin(); it != a.end(); it++)

ostream& operator<<(ostream& os, const vector<char>& vec) {
  os << "{";
  foreach (it, vec) { os << (it == vec.begin() ? "" : " ") << *it; }
  return os << "}";
}

template <class A> ostream& operator<<(ostream& os, const vector<A>& vec) {
  os << "{";
  foreach (it, vec) { os << (it == vec.begin() ? "" : ", ") << *it; }
  return os << "}";
}

template <class A> ostream& operator<<(ostream& os, const vector<vector<A> >& vec) {
  os << "{\n";
  foreach (it, vec) { os << (it == vec.begin() ? " " : "\n ") << *it; }
  return os << "\n}";
}

template <class A> ostream& operator<<(ostream& os, const vector<vector<vector<A> > >& vec) {
  os << "{\n";
  foreach (it, vec) { os << (it == vec.begin() ? "" : "\n") << it - vec.begin() << ": " << *it; }
  return os << "\n}";
}

template <class A> ostream& operator<<(ostream& os, const set<A>& se) {
  os << "{";
  foreach (it, se) { os << (it == se.begin() ? "" : ", ") << *it; }
  return os << "}";
}

template <class A> ostream& operator<<(ostream& os, const multiset<A>& ms) {
  os << "{";
  foreach (it, ms) { os << (it == ms.begin() ? "" : ", ") << *it; }
  return os << "}";
}

template <class A, class B> ostream& operator<<(ostream& os, const map<A, B>& ma) {
  os << "{";
  foreach (it, ma) { os << (it == ma.begin() ? "" : ", ") << *it; }
  return os << "}";
}

template <class A> ostream& operator<<(ostream& os, priority_queue<A> pq) {
  os << "{";
  while (!pq.empty()) {
    os << pq.top(), pq.pop();
    if (!pq.empty()) os << ", ";
  }
  return os << "}";
}

template <class A, class B> ostream& operator<<(ostream& os, const pair<A, B>& p) {
  const auto& [a, b] = p;
  return os << "(" << a << ", " << b << ")";
}

template <class A, class B, class C> ostream& operator<<(ostream& os, const tuple<A, B, C>& t) {
  const auto& [a, b, c] = t;
  return os << "(" << a << ", " << b << ", " << c << ")";
}

template <class A, class B, class C, class D> ostream& operator<<(ostream& os, const tuple<A, B, C, D>& t) {
  const auto& [a, b, c, d] = t;
  return os << "(" << a << ", " << b << ", " << c << ", " << d << ")";
}

void dump_func() {}
template <class A, class... B> void dump_func(const A& a, const B&... b) {
  cout << a << (sizeof...(b) ? ", " : "\n");
  dump_func(b...);
}

#ifdef _DEBUG
#define dump(...) cout << "[" << (#__VA_ARGS__) << "]: ", dump_func(__VA_ARGS__)
#else
#define dump(...)
#endif
#endif
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