Submission #656100

#	Time	Username	Problem	Language	Result	Execution time	Memory
656100		600Mihnea	Necklace (Subtask 4) (BOI19_necklace4)	C++17	0 / 15	0 ms	212 KiB

necklace

bool home = 1;
bool verbose = 1;

#include <bits/stdc++.h>

using namespace std;

mt19937 rng(7777);

typedef long double ld;

const ld PI = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196442881097566593344612847564823378678316527120190914;
using cd = complex<ld>;

ld values[26];

cd get(string s, cd c) {
  cd sol = 0;
  cd cur = 1;
  for (int i = 0; i < (int) s.size(); i++) {
    assert('a' <= s[i] && s[i] <= 'z');
    sol += cur * values[s[i] - 'a'];
    cur *= c;
  }
  return sol;
}

bool same(string s, string t) {
  assert((int) s.size() == (int) t.size());
  int n = (int) s.size();
  ld ang = 2 * PI / n;
  cd c(cos(ang), sin(ang));
  /// get(s, c) == get(t, c) * c sau get(s, c) == get(t, c) * c^2 sau ...
  return abs(norm(get(s, c)) - norm(get(t, c))) < 1e-6;
  cd val = get(s, c) / get(t, c);
  cout << fixed << setprecision(3) << val << "\n";
  cout << fixed << setprecision(3) << c << "\n";
  cout << fixed << setprecision(3) << c * c << "\n";
  cout << fixed << setprecision(3) << c * c * c << "\n";
}

string s, t;

bool isok(int len) {
  int n = (int) s.size();
  int m = (int) t.size();
  for (int i = 0; i + len - 1 < n; i++) {
    for (int j = 0; j + len - 1 < m; j++) {
      bool ok = same(string(s.begin() + i, s.begin() + i + len), string(t.begin() + j, t.begin() + j + len));
      if (ok) {
        return 1;
      }
    }
  }
  return 0;
}

int main() {
  for (int x = 0; x < 26; x++) {
    values[x] = cos(rng()) * 10;
  }
  if (!home) {
    verbose = 0;
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
  }
  if (home) {
    verbose = 1;
    freopen ("___input___.txt", "r", stdin);
  }

  cin >> s >> t;
  int n = (int) s.size(), m = (int) t.size();
  int sol = min(n, m);
  while (!isok(sol)) {
    sol--;
  }
  cout << sol << "\n";
  return 0;
}

Compilation message (stderr)

necklace.cpp: In function 'int main()':
necklace.cpp:70:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |     freopen ("___input___.txt", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15