Submission #657078

# Submission time Handle Problem Language Result Execution time Memory
657078 2022-11-08T20:01:58 Z bicsi Necklace (Subtask 1-3) (BOI19_necklace1) C++14
45 / 85
653 ms 736 KB
#include <bits/stdc++.h>

using namespace std;
using ld = long double;

using C = complex<ld>;
const ld EPS = 1e-8;

int main() {
  string s, t; cin >> s >> t;

  mt19937_64 rng(52);
  vector<C> rnd(256);
  for (int i = 0; i < 256; ++i) {
    ld real = 1.0L * rng() / rng.max();
    ld imag = 1.0L * rng() / rng.max();
    rnd[i] = C(real, imag);
    rnd[i] /= abs(rnd[i]);
  }

  auto cmp = [&](const pair<C, int>& aa, const pair<C, int>& bb) {
    auto& a = aa.first;
    auto& b = bb.first;
    if (abs(a.real() - b.real()) > EPS) 
      return a.real() < b.real();
    if (abs(a.imag() - b.imag()) > EPS) 
      return a.imag() < b.imag();
    return false;
  };
  
  vector<pair<C, int>> vs, vt;
  auto check = [&](int len) {
    C eps = polar(1.0, 2.0 * M_PI / len);
    pair<int, int> ans = {-1, -1};
    for (int rev = 0; rev < 2; ++rev) {
      vs.clear(); vt.clear();
      for (int it = 0; it < 2; ++it) {
        C h = 0;
        for (int i = 0; i < (int)s.size(); ++i) {
          h = (h + rnd[s[i]]) * eps;
          if (i >= len - 1) {
            C now = polar(abs(h), arg(h) * len);
            vs.emplace_back(now, i - len + 1);
            h -= rnd[s[i - len + 1]];
          }
        }
        swap(s, t); swap(vs, vt);
      }
      sort(vs.begin(), vs.end(), cmp);
      sort(vt.begin(), vt.end(), cmp);
      for (int i = 0, j = 0; i < (int)vs.size(); ++i) {
        while (j < vt.size() && !cmp(vs[i], vt[j])) {
          if (!cmp(vt[j], vs[i])) {
            ans.first = vs[i].second;
            ans.second = vt[j].second;
            if (rev) ans.first = s.size() - ans.first - len;
          }
          ++j;
        }
      }
      reverse(s.begin(), s.end());
    }
    return ans;
  };

  int ans = 0, ps = -1, pt = -1;
  int bound = 1;
  while (check(bound).first >= 0) bound *= 2;
  for (int i = bound; i >= bound/2; --i) {
    auto [a, b] = check(i);
    if (a >= 0) {
      ans = i, ps = a, pt = b;
      break;
    }
  }
  cout << ans << endl << ps << " " << pt << endl;

  return 0;
}

Compilation message

necklace.cpp: In lambda function:
necklace.cpp:52:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::complex<long double>, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |         while (j < vt.size() && !cmp(vs[i], vt[j])) {
      |                ~~^~~~~~~~~~~
necklace.cpp: In function 'int main()':
necklace.cpp:70:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   70 |     auto [a, b] = check(i);
      |          ^
# Verdict Execution time Memory Grader output
1 Correct 2 ms 212 KB Output is correct
2 Correct 2 ms 212 KB Output is correct
3 Correct 4 ms 212 KB Output is correct
4 Correct 2 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 212 KB Output is correct
2 Correct 2 ms 212 KB Output is correct
3 Correct 4 ms 212 KB Output is correct
4 Correct 2 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 12 ms 372 KB Output is correct
7 Correct 14 ms 376 KB Output is correct
8 Correct 12 ms 340 KB Output is correct
9 Correct 22 ms 340 KB Output is correct
10 Correct 53 ms 340 KB Output is correct
11 Correct 34 ms 356 KB Output is correct
12 Correct 24 ms 376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 212 KB Output is correct
2 Correct 2 ms 212 KB Output is correct
3 Correct 4 ms 212 KB Output is correct
4 Correct 2 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 12 ms 372 KB Output is correct
7 Correct 14 ms 376 KB Output is correct
8 Correct 12 ms 340 KB Output is correct
9 Correct 22 ms 340 KB Output is correct
10 Correct 53 ms 340 KB Output is correct
11 Correct 34 ms 356 KB Output is correct
12 Correct 24 ms 376 KB Output is correct
13 Correct 524 ms 732 KB Output is correct
14 Correct 490 ms 736 KB Output is correct
15 Correct 571 ms 712 KB Output is correct
16 Correct 653 ms 732 KB Output is correct
17 Correct 247 ms 716 KB Output is correct
18 Correct 221 ms 732 KB Output is correct
19 Incorrect 76 ms 712 KB Output isn't correct
20 Halted 0 ms 0 KB -