結果
| 問題 | No.1773 Love Triangle |
| ユーザー |
 theory_and_me
|
| 提出日時 | 2021-12-16 00:02:21 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 1,354 ms / 2,000 ms |
| コード長 | 6,471 bytes |
| コンパイル時間 | 5,779 ms |
| コンパイル使用メモリ | 210,008 KB |
| 最終ジャッジ日時 | 2025-01-26 23:26:07 |
|
ジャッジサーバーID （参考情報） |
judge1 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 90 |
ソースコード
#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;
#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x) cerr << "Line " << __LINE__ << ": " << #x << " = " << (x) << "\n";
#define spa << " " <<
#define fi first
#define se second
#define ALL(a) (a).begin(),(a).end()
#define ALLR(a) (a).rbegin(),(a).rend()
using ld = long double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
template<typename T> using V = vector<T>;
template<typename T> using P = pair<T, T>;
template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){os << "(" << v.first << ", " << v.second << ")"; return os;}
template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> ostream& operator<<(ostream& os, const vector<vector<T>> &v){ for(auto &e : v){os << e << "\n";} return os;}
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
template <class T> void UNIQUE(vector<T> &x) {sort(ALL(x));x.erase(unique(ALL(x)), x.end());}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
void fail() { cout << -1 << '\n'; exit(0); }
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<"\n";}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<"\n";};
const ll INF = (1ll<<62);
// const ld EPS = 1e-10;
// const ld PI = acos(-1.0);
const ll mod = (int)1e9 + 7;
//const ll mod = 998244353;
unsigned int randxor(){
static unsigned int x=123456789,y=362436069,z=521288629,w=88675123;
unsigned int t;
t=(x^(x<<11));x=y;y=z;z=w; return( w=(w^(w>>19))^(t^(t>>8)) );
}
using mint = modint1000000007;
// https://ei1333.github.io/library/library/math/matrix/matrix.cpp.html
template< class T >
struct Matrix {
vector< vector< T > > A;
Matrix() {}
Matrix(int n, int m) : A(n, vector< T >(m, 0)) {}
Matrix(int n) : A(n, vector< T >(n, 0)) {};
int height() const {
return (int)(A.size());
}
int width() const {
return (int)(A[0].size());
}
inline const vector< T > &operator[](int k) const {
return (A.at(k));
}
inline vector< T > &operator[](int k) {
return (A.at(k));
}
static Matrix I(int n) {
Matrix mat(n);
for(int i = 0; i < n; i++) mat[i][i] = 1;
return (mat);
}
Matrix &operator+=(const Matrix &B) {
size_t n = height(), m = width();
assert(n == B.height() && m == B.width());
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
(*this)[i][j] += B[i][j];
return (*this);
}
Matrix &operator-=(const Matrix &B) {
size_t n = height(), m = width();
assert(n == B.height() && m == B.width());
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
(*this)[i][j] -= B[i][j];
return (*this);
}
Matrix &operator*=(const Matrix &B) {
int n = height(), m = B.width(), p = width();
assert(p == B.height());
vector< vector< T > > C(n, vector< T >(m, 0));
for(int i = 0; i < n; i++)
for(int j = 0; j < m; j++)
for(int k = 0; k < p; k++)
C[i][j] = (C[i][j] + (*this)[i][k] * B[k][j]);
A.swap(C);
return (*this);
}
Matrix &operator^=(long long k) {
Matrix B = Matrix::I(height());
while(k > 0) {
if(k & 1) B *= *this;
*this *= *this;
k >>= 1LL;
}
A.swap(B.A);
return (*this);
}
Matrix operator+(const Matrix &B) const {
return (Matrix(*this) += B);
}
Matrix operator-(const Matrix &B) const {
return (Matrix(*this) -= B);
}
Matrix operator*(const Matrix &B) const {
return (Matrix(*this) *= B);
}
Matrix operator^(const long long k) const {
return (Matrix(*this) ^= k);
}
friend ostream &operator<<(ostream &os, Matrix &p) {
size_t n = p.height(), m = p.width();
for(int i = 0; i < n; i++) {
os << "[";
for(int j = 0; j < m; j++) {
os << p[i][j] << (j + 1 == m ? "]\n" : ",");
}
}
return (os);
}
int rank(){
Matrix B(*this);
int res = 0;
for(int k=0;k<width();k++){
for(int i=res+1;i<height()&&(B[res][k]==0);i++){
if(B[i][k]!=0)swap(B[i],B[res]);
}
if(B[res][k]==0)continue;
for(int l=k+1;l<width();l++)B[res][l]/=B[res][k];
for(int j=res+1;j<height();j++)
for(int l=k+1;l<width();l++)
B[j][l]-=B[j][k]*B[res][l];
res++;
}
return res;
}
T determinant() {
Matrix B(*this);
assert(width() == height());
T ret = 1;
for(int i = 0; i < width(); i++) {
int idx = -1;
for(int j = i; j < width(); j++) {
if(B[j][i] != 0) idx = j;
}
if(idx == -1) return (0);
if(i != idx) {
ret *= -1;
swap(B[i], B[idx]);
}
ret *= B[i][i];
T vv = B[i][i];
for(int j = 0; j < width(); j++) {
B[i][j] /= vv;
}
for(int j = i + 1; j < width(); j++) {
T a = B[j][i];
for(int k = 0; k < width(); k++) {
B[j][k] -= B[i][k] * a;
}
}
}
return (ret);
}
};
int main(){
int N, M;
cin >> N >> M;
vector<int> u(M), v(M), w(M);
REP(i, M) cin >> u[i] >> v[i] >> w[i], u[i]--, v[i]--, w[i]--;
map<int, int> mp;
REP(t, 10){
Matrix<mint> X(N, N);
REP(i, M){
int r = randxor() % mod;
X[u[i]][v[i]] += r;
X[u[i]][w[i]] -= r;
X[w[i]][v[i]] -= r;
X[v[i]][u[i]] -= r;
X[v[i]][w[i]] += r;
X[w[i]][u[i]] += r;
}
int rank = X.rank();
mp[rank/2] += 1;
}
int ma = 0, res = 0;
for(auto x: mp){
if(chmax(ma, x.second)) res = x.first;
}
cout << res << endl;
return 0;
}