Submission #657094

# Submission time Handle Problem Language Result Execution time Memory
657094 2022-11-08T21:26:35 Z bicsi Necklace (Subtask 1-3) (BOI19_necklace1) C++14
45 / 85
175 ms 632 KB
#include <bits/stdc++.h>

using namespace std;
using ld = long double;

using C = complex<ld>;
const ld EPS = 1e-7;

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]);
  }
  
  vector<pair<ld, 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) {
            vs.emplace_back(norm(h), i - len + 1);
            h -= rnd[s[i - len + 1]];
          }
        }
        swap(s, t); swap(vs, vt);
      }
      sort(vs.begin(), vs.end());
      sort(vt.begin(), vt.end());
      for (int i = 0, j = 0; i < (int)vs.size(); ++i) {
        while (j < vt.size() && vs[i].first + EPS > vt[j].first) {
          if (abs(vt[j].first - vs[i].first) < EPS) {
            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:41:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long double, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |         while (j < vt.size() && vs[i].first + EPS > vt[j].first) {
      |                ~~^~~~~~~~~~~
necklace.cpp: In function 'int main()':
necklace.cpp:59:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   59 |     auto [a, b] = check(i);
      |          ^
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 4 ms 340 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 4 ms 340 KB Output is correct
10 Correct 8 ms 356 KB Output is correct
11 Correct 6 ms 356 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 300 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 4 ms 340 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 2 ms 340 KB Output is correct
9 Correct 4 ms 340 KB Output is correct
10 Correct 8 ms 356 KB Output is correct
11 Correct 6 ms 356 KB Output is correct
12 Correct 4 ms 340 KB Output is correct
13 Correct 175 ms 632 KB Output is correct
14 Correct 170 ms 628 KB Output is correct
15 Incorrect 49 ms 596 KB Output isn't correct
16 Halted 0 ms 0 KB -