oj.uz

Submission #557677

# Submission time Handle Problem Language Result Execution time Memory
557677 2022-05-05T18:34:19 Z Soumya1 Necklace (Subtask 1-3) (BOI19_necklace1) C++17
85 / 85
 429 ms 560 KB 
#include <bits/stdc++.h>
#ifdef __LOCAL__
#include <debug_local.h>
#endif
using namespace std;
vector<int> prefix_function(string &s) {
  int n = s.size();
  vector<int> pi(n);
  for (int i = 1; i < n; i++) {
    int j = pi[i - 1];
    while (j > 0 && s[j] != s[i]) j = pi[j - 1];
    if (s[j] == s[i]) j++;
    pi[i] = j;
  }
  return pi;
}
vector<int> suffix_function(string s) { // :P there is no such thing. I just named it (actually same as prefix function)
  int n = s.size();
  vector<int> pi(n);
  pi[n - 1] = n - 1;
  for (int i = n - 2; i >= 0; i--) {
    int j = pi[i + 1];
    while (j < n - 1 && s[j] != s[i]) j = pi[j + 1];
    if (s[j] == s[i]) j--;
    pi[i] = j;
  }
  for (int &i : pi) {
    i = n - 1 - i;
  }
  return pi;
}
tuple<int, int, int> solve(string s, string t, bool f = false) {
  int n = s.size(), m = t.size();
  tuple<int, int, int> ret = {0, 0, 0};
  for (int i = 0; i < n; i++) {
    string s1 = s.substr(0, i);
    string s2 = s.substr(i, n - i);
    string ss1 = s2 + '#' + t;
    string ss2 = t + '#' + s1;
    auto pi = prefix_function(ss1);
    auto si = suffix_function(ss2);
    int a[m], b[m];
    memset(a, 0, sizeof a);
    memset(b, 0, sizeof b);
    for (int j = 0; j < m; j++) {
      a[j] = pi[j + n - i + 1];
      b[j] = si[j];
    }
    for (int j = 0; j < m; j++) {
      ret = max(ret, {a[j], i, j - a[j] + 1});
      ret = max(ret, {b[j], i - b[j], j});
      if (j >= 1) {
        ret = max(ret, {a[j - 1] + b[j], i - b[j], j - a[j - 1]});
      }
    }
  }
  if (f) {
    auto &[l, i, j] = ret;
    i = n - i - l;
  }
  return ret;
}
void testCase() {
  string s, t;
  cin >> s >> t;
  auto a = solve(s, t);
  reverse(s.begin(), s.end());
  auto b = solve(s, t, true);
  a = max(a, b);
  auto [l, i, j] = a;
  cout << l << "\n";
  cout << i << " " << j << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  testCase();
  return 0;
}

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 284 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 284 KB Output is correct
6 Correct 10 ms 340 KB Output is correct
7 Correct 8 ms 360 KB Output is correct
8 Correct 9 ms 368 KB Output is correct
9 Correct 8 ms 340 KB Output is correct
10 Correct 8 ms 340 KB Output is correct
11 Correct 8 ms 368 KB Output is correct
12 Correct 9 ms 340 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 284 KB Output is correct
6 Correct 10 ms 340 KB Output is correct
7 Correct 8 ms 360 KB Output is correct
8 Correct 9 ms 368 KB Output is correct
9 Correct 8 ms 340 KB Output is correct
10 Correct 8 ms 340 KB Output is correct
11 Correct 8 ms 368 KB Output is correct
12 Correct 9 ms 340 KB Output is correct
13 Correct 426 ms 560 KB Output is correct
14 Correct 423 ms 520 KB Output is correct
15 Correct 429 ms 544 KB Output is correct
16 Correct 410 ms 464 KB Output is correct
17 Correct 353 ms 560 KB Output is correct
18 Correct 350 ms 416 KB Output is correct
19 Correct 390 ms 464 KB Output is correct
20 Correct 393 ms 468 KB Output is correct
21 Correct 424 ms 528 KB Output is correct