結果

問題 No.3257 +|+
ユーザー dyktr_06
提出日時 2025-09-05 23:28:42
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 689 ms / 3,000 ms
コード長 15,230 bytes
コンパイル時間 4,613 ms
コンパイル使用メモリ 262,332 KB
実行使用メモリ 93,396 KB
最終ジャッジ日時 2025-09-05 23:29:04
合計ジャッジ時間 20,489 ms
ジャッジサーバーID
(参考情報)
judge3 / judge2
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 3
other AC * 33
権限があれば一括ダウンロードができます
コンパイルメッセージ
hashmap/hashmap-base.hpp:15:7: warning: ‘template<class _Category, class _Tp, class _Distance, class _Pointer, class _Reference> struct std::iterator’ is deprecated [-Wdeprecated-declarations]
In file included from /usr/include/c++/13/bits/stl_algobase.h:65,
                 from /usr/include/c++/13/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:51,
                 from main.cpp:1:
/usr/include/c++/13/bits/stl_iterator_base_types.h:127:34: note: declared here
  127 |     struct _GLIBCXX17_DEPRECATED iterator
      |                                  ^~~~~~~~
hashmap/hashmap-base.hpp:17:7: warning: ‘template<class _Category, class _Tp, class _Distance, class _Pointer, class _Reference> struct std::iterator’ is deprecated [-Wdeprecated-declarations]
/usr/include/c++/13/bits/stl_iterator_base_types.h:127:34: note: declared here
  127 |     struct _GLIBCXX17_DEPRECATED iterator
      |                                  ^~~~~~~~

ソースコード

diff #

#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;
using namespace atcoder;

#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for(int i = 0; i < (int)(n); ++i)
#define rep2(i, n) for(int i = 0; i < (int)(n); ++i)
#define rep3(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep4(i, a, b, c) for(int i = (a); i < (int)(b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)

#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; --i)
#define ALL(a) (a).begin(), (a).end()
#define Sort(a) (sort((a).begin(), (a).end()))
#define RSort(a) (sort((a).rbegin(), (a).rend()))
#define UNIQUE(a) (a.erase(unique((a).begin(), (a).end()), (a).end()))

typedef long long int ll;
typedef unsigned long long ul;
typedef long double ld;
typedef vector<int> vi;
typedef vector<long long> vll;
typedef vector<char> vc;
typedef vector<string> vst;
typedef vector<double> vd;
typedef vector<long double> vld;
typedef pair<long long, long long> P;

template<class T> long long sum(const T &a){ return accumulate(a.begin(), a.end(), 0LL); }
template<class T> auto min(const T &a){ return *min_element(a.begin(), a.end()); }
template<class T> auto max(const T &a){ return *max_element(a.begin(), a.end()); }

const long long MINF = 0x7fffffffffff;
const long long INF = 0x1fffffffffffffff;
const long long MOD = 998244353;
const long double EPS = 1e-9;
const long double PI = acos(-1);

template<class T> inline bool chmax(T &a, T b) { if(a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T &a, T b) { if(a > b) { a = b; return 1; } return 0; }

template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p){ is >> p.first >> p.second; return is; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){ os << "(" << p.first << ", " << p.second << ")"; return os; }
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for(T &in : v) is >> in; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v){ for(int i = 0; i < (int) v.size(); ++i){ os << v[i] << (i + 1 != (int) v.size() ? " " : ""); } return os; }
template <typename T, typename S> ostream &operator<<(ostream &os, const map<T, S> &mp){ for(auto &[key, val] : mp){ os << key << ":" << val << " "; } return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, queue<T> q){ while(q.size()){ os << q.front() << " "; q.pop(); } return os; }
template <typename T> ostream &operator<<(ostream &os, deque<T> q){ while(q.size()){ os << q.front() << " "; q.pop_front(); } return os; }
template <typename T> ostream &operator<<(ostream &os, stack<T> st){ while(st.size()){ os << st.top() << " "; st.pop(); } return os; }
template <class T, class Container, class Compare> ostream &operator<<(ostream &os, priority_queue<T, Container, Compare> pq){ while(pq.size()){ os << pq.top() << " "; pq.pop(); } return os; }

template <typename T>
long long binary_search(long long ok, long long ng, T check){
    while(abs(ok - ng) > 1){
        long long mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

template <typename T>
long double binary_search_real(long double ok, long double ng, T check, int iter = 100){
    for(int i = 0; i < iter; ++i){
        long double mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

template <typename T>
long long trisum(T a, T b){
    long long res = ((b - a + 1) * (a + b)) / 2;
    return res;
}

template <typename T>
T intpow(T x, int n){
    T ret = 1;
    while(n > 0) {
        if(n & 1) (ret *= x);
        (x *= x);
        n >>= 1;
    }
    return ret;
}

template <typename T>
T getReminder(T a, T b){
    if(b == 0) return -1;
    if(a >= 0 && b > 0){
        return a % b;
    } else if(a < 0 && b > 0){
        return ((a % b) + b) % b;
    } else if(a >= 0 && b < 0){
        return a % b;
    } else{
        return (abs(b) - abs(a % b)) % b;
    }
}

template<class T, class U> inline T vin(T &vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; }
template<class T> inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; }
template<class... T> void in(T&... a){ (cin >> ... >> a); }
void out(){ cout << '\n'; }
template<class T, class... Ts> void out(const T &a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; }
template<class T, class U> void inGraph(vector<vector<T>> &G, U n, U m, bool directed = false){ G.resize(n); for(int i = 0; i < m; ++i){ int a, b; cin >> a >> b; a--, b--; G[a].push_back(b); if(!directed) G[b].push_back(a); } }

// https://nyaannyaan.github.io/library/hashmap/hashmap.hpp.html
#line 2 "hashmap/hashmap.hpp"

#line 2 "hashmap/hashmap-base.hpp"

#include <cstdint>
using namespace std;

namespace HashMapImpl {
using u32 = uint32_t;
using u64 = uint64_t;

template <typename Key, typename Data>
struct HashMapBase;

template <typename Key, typename Data>
struct itrB
    : iterator<bidirectional_iterator_tag, Data, ptrdiff_t, Data*, Data&> {
  using base =
      iterator<bidirectional_iterator_tag, Data, ptrdiff_t, Data*, Data&>;
  using ptr = typename base::pointer;
  using ref = typename base::reference;

  u32 i;
  HashMapBase<Key, Data>* p;

  explicit constexpr itrB() : i(0), p(nullptr) {}
  explicit constexpr itrB(u32 _i, HashMapBase<Key, Data>* _p) : i(_i), p(_p) {}
  explicit constexpr itrB(u32 _i, const HashMapBase<Key, Data>* _p)
      : i(_i), p(const_cast<HashMapBase<Key, Data>*>(_p)) {}
  friend void swap(itrB& l, itrB& r) { swap(l.i, r.i), swap(l.p, r.p); }
  friend bool operator==(const itrB& l, const itrB& r) { return l.i == r.i; }
  friend bool operator!=(const itrB& l, const itrB& r) { return l.i != r.i; }
  const ref operator*() const {
    return const_cast<const HashMapBase<Key, Data>*>(p)->data[i];
  }
  ref operator*() { return p->data[i]; }
  ptr operator->() const { return &(p->data[i]); }

  itrB& operator++() {
    assert(i != p->cap && "itr::operator++()");
    do {
      i++;
      if (i == p->cap) break;
      if (p->occupied_flag[i] && !p->deleted_flag[i]) break;
    } while (true);
    return (*this);
  }
  itrB operator++(int) {
    itrB it(*this);
    ++(*this);
    return it;
  }
  itrB& operator--() {
    do {
      i--;
      if (p->occupied_flag[i] && !p->deleted_flag[i]) break;
      assert(i != 0 && "itr::operator--()");
    } while (true);
    return (*this);
  }
  itrB operator--(int) {
    itrB it(*this);
    --(*this);
    return it;
  }
};

template <typename Key, typename Data>
struct HashMapBase {
  using u32 = uint32_t;
  using u64 = uint64_t;
  using iterator = itrB<Key, Data>;
  using itr = iterator;

 protected:
  template <typename K>
  inline u64 randomized(const K& key) const {
    return u64(key) ^ r;
  }

  template <typename K,
            enable_if_t<is_same<K, Key>::value, nullptr_t> = nullptr,
            enable_if_t<is_integral<K>::value, nullptr_t> = nullptr>
  inline u32 inner_hash(const K& key) const {
    return (randomized(key) * 11995408973635179863ULL) >> shift;
  }
  template <
      typename K, enable_if_t<is_same<K, Key>::value, nullptr_t> = nullptr,
      enable_if_t<is_integral<decltype(K::first)>::value, nullptr_t> = nullptr,
      enable_if_t<is_integral<decltype(K::second)>::value, nullptr_t> = nullptr>
  inline u32 inner_hash(const K& key) const {
    u64 a = randomized(key.first), b = randomized(key.second);
    a *= 11995408973635179863ULL;
    b *= 10150724397891781847ULL;
    return (a + b) >> shift;
  }
  template <typename K,
            enable_if_t<is_same<K, Key>::value, nullptr_t> = nullptr,
            enable_if_t<is_integral<typename K::value_type>::value, nullptr_t> =
                nullptr>
  inline u32 inner_hash(const K& key) const {
    static constexpr u64 mod = (1LL << 61) - 1;
    static constexpr u64 base = 950699498548472943ULL;
    u64 res = 0;
    for (auto& elem : key) {
      __uint128_t x = __uint128_t(res) * base + (randomized(elem) & mod);
      res = (x & mod) + (x >> 61);
    }
    __uint128_t x = __uint128_t(res) * base;
    res = (x & mod) + (x >> 61);
    if (res >= mod) res -= mod;
    return res >> (shift - 3);
  }

  template <typename D = Data,
            enable_if_t<is_same<D, Key>::value, nullptr_t> = nullptr>
  inline u32 hash(const D& dat) const {
    return inner_hash(dat);
  }
  template <
      typename D = Data,
      enable_if_t<is_same<decltype(D::first), Key>::value, nullptr_t> = nullptr>
  inline u32 hash(const D& dat) const {
    return inner_hash(dat.first);
  }

  template <typename D = Data,
            enable_if_t<is_same<D, Key>::value, nullptr_t> = nullptr>
  inline Key data_to_key(const D& dat) const {
    return dat;
  }
  template <
      typename D = Data,
      enable_if_t<is_same<decltype(D::first), Key>::value, nullptr_t> = nullptr>
  inline Key data_to_key(const D& dat) const {
    return dat.first;
  }

  void reallocate(u32 ncap) {
    vector<Data> ndata(ncap);
    vector<bool> nf(ncap);
    shift = 64 - __lg(ncap);
    for (u32 i = 0; i < cap; i++) {
      if (occupied_flag[i] && !deleted_flag[i]) {
        u32 h = hash(data[i]);
        while (nf[h]) h = (h + 1) & (ncap - 1);
        ndata[h] = move(data[i]);
        nf[h] = true;
      }
    }
    data.swap(ndata);
    occupied_flag.swap(nf);
    cap = ncap;
    occupied = s;
    deleted_flag.resize(cap);
    fill(std::begin(deleted_flag), std::end(deleted_flag), false);
  }

  inline bool extend_rate(u32 x) const { return x * 2 >= cap; }

  inline bool shrink_rate(u32 x) const {
    return HASHMAP_DEFAULT_SIZE < cap && x * 10 <= cap;
  }

  inline void extend() { reallocate(cap << 1); }

  inline void shrink() { reallocate(cap >> 1); }

 public:
  u32 cap, s, occupied;
  vector<Data> data;
  vector<bool> occupied_flag, deleted_flag;
  u32 shift;
  static u64 r;
  static constexpr uint32_t HASHMAP_DEFAULT_SIZE = 4;

  explicit HashMapBase()
      : cap(HASHMAP_DEFAULT_SIZE),
        s(0),
        occupied(0),
        data(cap),
        occupied_flag(cap),
        deleted_flag(cap),
        shift(64 - __lg(cap)) {}

  itr begin() const {
    u32 h = 0;
    while (h != cap) {
      if (occupied_flag[h] && !deleted_flag[h]) break;
      h++;
    }
    return itr(h, this);
  }
  itr end() const { return itr(this->cap, this); }

  friend itr begin(const HashMapBase& h) { return h.begin(); }
  friend itr end(const HashMapBase& h) { return h.end(); }

  itr find(const Key& key) const {
    u32 h = inner_hash(key);
    while (true) {
      if (occupied_flag[h] == false) return this->end();
      if (data_to_key(data[h]) == key) {
        if (deleted_flag[h] == true) return this->end();
        return itr(h, this);
      }
      h = (h + 1) & (cap - 1);
    }
  }

  bool contain(const Key& key) const { return find(key) != this->end(); }

  itr insert(const Data& d) {
    u32 h = hash(d);
    while (true) {
      if (occupied_flag[h] == false) {
        if (extend_rate(occupied + 1)) {
          extend();
          h = hash(d);
          continue;
        }
        data[h] = d;
        occupied_flag[h] = true;
        ++occupied, ++s;
        return itr(h, this);
      }
      if (data_to_key(data[h]) == data_to_key(d)) {
        if (deleted_flag[h] == true) {
          data[h] = d;
          deleted_flag[h] = false;
          ++s;
        }
        return itr(h, this);
      }
      h = (h + 1) & (cap - 1);
    }
  }

  // tips for speed up :
  // if return value is unnecessary, make argument_2 false.
  itr erase(itr it, bool get_next = true) {
    if (it == this->end()) return this->end();
    s--;
    if (!get_next) {
      this->deleted_flag[it.i] = true;
      if (shrink_rate(s)) shrink();
      return this->end();
    }
    itr nxt = it;
    nxt++;
    this->deleted_flag[it.i] = true;
    if (shrink_rate(s)) {
      Data d = data[nxt.i];
      shrink();
      it = find(data_to_key(d));
    }
    return nxt;
  }

  itr erase(const Key& key) { return erase(find(key)); }

  int count(const Key& key) { return find(key) == end() ? 0 : 1; }

  bool empty() const { return s == 0; }

  int size() const { return s; }

  void clear() {
    fill(std::begin(occupied_flag), std::end(occupied_flag), false);
    fill(std::begin(deleted_flag), std::end(deleted_flag), false);
    s = occupied = 0;
  }

  void reserve(int n) {
    if (n <= 0) return;
    n = 1 << min(23, __lg(n) + 2);
    if (cap < u32(n)) reallocate(n);
  }
};

template <typename Key, typename Data>
uint64_t HashMapBase<Key, Data>::r =
    chrono::duration_cast<chrono::nanoseconds>(
        chrono::high_resolution_clock::now().time_since_epoch())
        .count();

}  // namespace HashMapImpl

/**
 * @brief Hash Map(base) (ハッシュマップ・基底クラス)
 */
#line 4 "hashmap/hashmap.hpp"

template <typename Key, typename Val>
struct HashMap : HashMapImpl::HashMapBase<Key, pair<Key, Val>> {
  using base = typename HashMapImpl::HashMapBase<Key, pair<Key, Val>>;
  using HashMapImpl::HashMapBase<Key, pair<Key, Val>>::HashMapBase;
  using Data = pair<Key, Val>;

  Val& operator[](const Key& k) {
    typename base::u32 h = base::inner_hash(k);
    while (true) {
      if (base::occupied_flag[h] == false) {
        if (base::extend_rate(base::occupied + 1)) {
          base::extend();
          h = base::hash(k);
          continue;
        }
        base::data[h].first = k;
        base::data[h].second = Val();
        base::occupied_flag[h] = true;
        ++base::occupied, ++base::s;
        return base::data[h].second;
      }
      if (base::data[h].first == k) {
        if (base::deleted_flag[h] == true) {
          base::data[h].second = Val();
          base::deleted_flag[h] = false;
          ++base::s;
        }
        return base::data[h].second;
      }
      h = (h + 1) & (base::cap - 1);
    }
  }

  typename base::itr emplace(const Key& key, const Val& val) {
    return base::insert(Data(key, val));
  }
};

/*
 * @brief ハッシュマップ(連想配列)
 * @docs docs/hashmap/hashmap.md
 **/

ll T;

void input(){
    in(T);
}

void solve(){
    ll n; in(n);
    vll a(n); in(a);
    const ll MAX_A = 200000;
    vector<vll> v(MAX_A + 1);
    rep(i, n){
        rep(j, 1, MAX_A + 1){
            ll val = a[i] - j * (i + 1);
            if(val < -MAX_A) break;
            v[j].push_back(val);
        }
    }

    ll ans = 0;
    rep(d, 1, MAX_A + 1){
        HashMap<ll, ll> mp;
        for(auto x : v[d]){
            ans += mp[-x];
            mp[x]++;
        }
    }
    out(ans);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);

    T = 1;
    // input();
    while(T--) solve();
}
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