結果
問題 | No.2355 Unhappy Back Dance |
ユーザー |
👑 ![]() |
提出日時 | 2023-04-08 18:26:47 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 4,147 ms / 6,000 ms |
コード長 | 3,732 bytes |
コンパイル時間 | 1,311 ms |
コンパイル使用メモリ | 111,688 KB |
最終ジャッジ日時 | 2025-02-12 03:59:17 |
ジャッジサーバーID (参考情報) |
judge2 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 37 |
ソースコード
#include <iostream> #include <vector> #include <set> #include <map> #include <utility> #include <algorithm> using namespace std; typedef long long ll; #define vl vector<ll> #define pll pair<ll,ll> 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]; } //map<ll, ll> mp1; //x軸に平行 //map<ll, ll> mp2; //y軸に平行 map<pair<pll, pll>, ll> mp3; //それ以外 vector<vector<pair<pll, pll>>> grad_vec(N, vector<pair<pll, pll>>(N)); for (ll i = 0; i < N; i++){ for (ll j = i + 1; j < N; j++){ if (X[i] == X[j]){ pair<ll,ll> g1 = pair<ll,ll>(X[i], 0); pair<ll,ll> g2 = pair<ll,ll>(-1, -1); mp3[pair<pll, pll>(g1, g2)]++; grad_vec[i][j] = pair<pll,pll>(g1, g2); } else if (Y[i] == Y[j]){ pair<ll,ll> g1 = pair<ll,ll>(0, Y[i]); pair<ll,ll> g2 = pair<ll,ll>(-1, -1); mp3[pair<pll, pll>(g1, g2)]++; grad_vec[i][j] = pair<pll, pll>(g1, g2); } else{ pll p1; pll p2; ll g1 = my_gcd(abs(Y[j] - Y[i]), abs(X[j] - X[i])); p1.first = (Y[j] - Y[i]) / g1; p1.second = (X[j] - X[i]) / g1; if (p1.second < 0){ p1.first *= -1; p1.second *= -1; } ll v1 = X[j] * Y[i] - X[i] * Y[j]; ll v2 = X[j] - X[i]; ll g2 = 1; if (v1 != 0){ g2 = my_gcd(abs(v1), abs(v2)); } else{ g2 = v2; } p2.first = v1 / g2; p2.second = v2 / g2; if (p2.second < 0){ p2.first *= -1; p2.second *= -1; } mp3[pair<pll, pll>(p1, p2)]++; grad_vec[i][j] = pair<pll,pll>(p1, p2); } } } ll now = 1; for (auto itr = mp3.begin(); itr != mp3.end(); itr++){ pair<pll, pll> p = itr->first; itr->second = now; now++; } vector<vector<ll>> grad_vec_num(N, vl(N)); for (ll i = 0; i < N; i++){ for (ll j = i + 1; j < N; j++){ grad_vec_num[i][j] = mp3[grad_vec[i][j]]; } } vector<set<ll>> set_vec(N * N / 2); for (ll i = 0; i < N; i++){ for (ll j = i + 1; j < N; j++){ set_vec[grad_vec_num[i][j]].insert(i); set_vec[grad_vec_num[i][j]].insert(j); } } vector<bool> pos(N, false); for (ll i = 0; i < N * N / 2; i++){ if (set_vec[i].size() <= 2){ continue; } else if (set_vec[i].size() >= 4){ for (auto itr = set_vec[i].begin(); itr != set_vec[i].end(); itr++){ pos[*itr] = true; } } else{ vector<pair<pll, ll>> st_to_vec(0); for (auto itr = set_vec[i].begin(); itr != set_vec[i].end(); itr++){ pll p = pll(X[*itr], Y[*itr]); st_to_vec.push_back(pair<pll, ll>(p, *itr)); } sort(st_to_vec.begin(), st_to_vec.end()); pos[st_to_vec[0].second] = true; pos[st_to_vec[2].second] = true; } } ll ans = 0; for (ll i = 0; i < N; i++){ if (pos[i]) ans++; } cout << ans << endl; }