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Submission #1073303

# Submission time Handle Problem Language Result Execution time Memory
1073303 2024-08-24T12:07:20 Z duckindog Necklace (Subtask 1-3) (BOI19_necklace1) C++17
45 / 85
 1500 ms 604 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 3000 + 10;
string s, t;

struct Hash { 
  using ull = unsigned long long;
  static const int base = 19937;
  int n;
  vector<ull> pw, h, rh;
  Hash(string s) : n(s.size()), pw(s.size() + 1), h(s.size() + 1), rh(s.size() + 1) { 
    pw[0] = 1;
    for (int i = 1; i <= n; ++i) pw[i] = pw[i - 1] * base;
    for (int i = 1; i <= n; ++i) h[i] = h[i - 1] * base + s[i - 1];
    for (int i = 1; i <= n; ++i) rh[i] = rh[i - 1] * base + s[n - i];
  } 
  ull get(int l, int r) { return h[r] - h[l - 1] * pw[r - l + 1]; }
  ull rget(int l, int r) { 
    tie(l, r) = make_pair(n - r + 1, n - l + 1);
    return rh[r] - rh[l - 1] * pw[r - l + 1]; 
  }
};

int f[N][N];

int32_t main() { 
  cin.tie(0)->sync_with_stdio(0);

  cin >> s >> t;
  int n = s.size(), m = t.size();

  tuple<int, int, int> answer;

  for (int type = 0; type < 2; ++ type) {
    Hash S(s), T(t);
    for (int i = 1; i < n; ++i) { 
      for (int j = 1; j < m; ++j) { 
        int prefix = 0;
        { //calculate prefix
          for (int x = 0; x <= min(i, j) - 1; ++x) 
            if (S.get(i - x, i) == T.rget(j - x, j)) prefix = x + 1;
        }

        int suffix = 0;
        { //calculate suffix
          for (int x = 1; x <= min(n - i, m - j); ++x) 
            if (S.get(i + 1, i + x) == T.rget(j + 1, j + x)) suffix = x;
        }
        
        tuple<int, int, int> ret;
        if (!type) ret = {prefix + suffix, i - prefix, j - prefix};
        else ret = {prefix + suffix, i - prefix, m - j - suffix};
        
        answer = max(answer, ret);
      }
    }
    reverse(t.begin(), t.end());
  }

  auto [lenght, i, j] = answer;
  cout << lenght << "\n";
  cout << i << " " << j << "\n";
}

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 KB Output is correct
5 Correct 2 ms 600 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 KB Output is correct
5 Correct 2 ms 600 KB Output is correct
6 Correct 100 ms 348 KB Output is correct
7 Correct 103 ms 344 KB Output is correct
8 Correct 87 ms 344 KB Output is correct
9 Correct 112 ms 604 KB Output is correct
10 Correct 98 ms 348 KB Output is correct
11 Correct 97 ms 460 KB Output is correct
12 Correct 109 ms 344 KB Output is correct

Subtask #3
0.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 2 ms 348 KB Output is correct
5 Correct 2 ms 600 KB Output is correct
6 Correct 100 ms 348 KB Output is correct
7 Correct 103 ms 344 KB Output is correct
8 Correct 87 ms 344 KB Output is correct
9 Correct 112 ms 604 KB Output is correct
10 Correct 98 ms 348 KB Output is correct
11 Correct 97 ms 460 KB Output is correct
12 Correct 109 ms 344 KB Output is correct
13 Execution timed out 1581 ms 604 KB Time limit exceeded
14 Halted 0 ms 0 KB -