結果
問題 |
No.2769 Number of Rhombi
|
ユーザー |
![]() |
提出日時 | 2024-06-01 18:56:57 |
言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 1,531 ms / 5,000 ms |
コード長 | 4,759 bytes |
コンパイル時間 | 19,887 ms |
コンパイル使用メモリ | 268,256 KB |
最終ジャッジ日時 | 2025-02-21 19:05:38 |
ジャッジサーバーID (参考情報) |
judge3 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 32 |
ソースコード
#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include <algorithm> #include <atcoder/all> #include <bitset> #include <cassert> #include <cmath> #include <ctime> #include <functional> #include <iomanip> #include <iostream> #include <map> #include <queue> #include <random> #include <set> #include <stack> #include <string> #include <tuple> #include <unordered_map> #include <unordered_set> #include <utility> #include <vector> using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector<int> #define vs vector<string> #define vc vector<char> #define vl vector<ll> #define vb vector<bool> #define vvi vector<vector<int>> #define vvc vector<vector<char>> #define vvl vector<vector<ll>> #define vvb vector<vector<bool>> #define vvvi vector<vector<vector<int>>> #define vvvl vector<vector<vector<ll>>> #define pii pair<int, int> #define pil pair<int, ll> #define pli pair<ll, int> #define pll pair<ll, ll> #define vpii vector<pair<int, int>> #define vpll vector<pair<ll, ll>> #define vvpii vector<vector<pair<int, int>>> #define vvpll vector<vector<pair<ll, ll>>> using mint = modint998244353; template <typename T> void debug(T e) { cerr << e << endl; } template <typename T> void debug(vector<T> &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template <typename T> void debug(vector<vector<T>> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template <typename T> void debug(vector<pair<T, T>> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template <typename T> void debug(set<T> &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template <typename T> void debug(multiset<T> &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template <typename T> void debug(map<T, T> &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } ll my_gcd(ll a, ll b) { ll ret = 0; if (a < b) { swap(a, b); } if (b == 0) { ret = a; } else { ret = my_gcd(b, a % b); } return ret; } int main() { ll N; cin >> N; vector<ll> x(N); vector<ll> y(N); for (ll i = 0; i < N; i++) { cin >> x[i] >> y[i]; } // 傾きと中央の点の座標の組を持つ map<pair<pll, pll>, ll> mp; for (ll i = 0; i < N; i++) { for (ll j = i + 1; j < N; j++) { ll fx = x[j] - x[i]; ll fy = y[j] - y[i]; ll cx = x[i] + x[j]; ll cy = y[i] + y[j]; if (fx == 0) { pll p = pll(0, 1); pll c = pll(cx, cy); mp[pair<pll, pll>(p, c)]++; } else if (fy == 0) { pll p = pll(1, 0); pll c = pll(cx, cy); mp[pair<pll, pll>(p, c)]++; } else { ll g = my_gcd(abs(fx), abs(fy)); fx /= g; fy /= g; if (fx < 0) { fx *= -1; fy *= -1; } pll p = pll(fx, fy); pll c = pll(cx, cy); mp[pair<pll, pll>(p, c)]++; } } } ll ans = 0; for (auto itr = mp.begin(); itr != mp.end(); itr++) { ll px = (itr->first).first.first; ll py = (itr->first).first.second; ll cx = (itr->first).second.first; ll cy = (itr->first).second.second; // debug_out(px, py, cx, cy, itr->second); if (px == 0) { pll p = pll(1, 0); pll c = pll(cx, cy); ans += itr->second * mp[pair<pll, pll>(p, c)]; } else if (py == 0) { pll p = pll(0, 1); pll c = pll(cx, cy); ans += itr->second * mp[pair<pll, pll>(p, c)]; } else { if (py < 0) { py *= -1; px *= -1; } pll p = pll(py, -px); pll c = pll(cx, cy); ans += itr->second * mp[pair<pll, pll>(p, c)]; } } cout << ans / 2 << endl; }