Submission #656182

# Submission time Handle Problem Language Result Execution time Memory
656182 2022-11-06T13:00:29 Z 600Mihnea Necklace (Subtask 1-3) (BOI19_necklace1) C++17
85 / 85
775 ms 71036 KB
bool home = 0;
bool verbose = 1;

#include <bits/stdc++.h>

using namespace std;

int comps = 0;

void compute(vector<vector<int>>& dp,string &s, string &t) {
  int n = (int) s.size();
  int m = (int) t.size();
  assert((int) dp.size() == n);
  for (int i = 0; i < n; i++) {
    assert((int) dp[i].size() == m);
  }
  for (auto &v : dp) {
    for (auto &x : v) {
      x = 0;
    }
  }
  for (int first = 0; first < m; first++) {
    string guy(t.begin() + first, t.end());
    int dim = (int) guy.size();
    vector<int> ps(dim, 0);
    int j = 0;
    for (int i = 1; i < dim; i++) {
      while (j && guy[i] != guy[j]) {
        j = ps[j - 1];
      }
      if (guy[i] == guy[j]) {
        j++;
      }
      ps[i] = j;
    }
    j = 0;
    for (int last = 0; last < n; last++) {
      while (j && s[last] != guy[j]) {
        j = ps[j - 1];
      }
      if (s[last] == guy[j]) {
        j++;
      }
      dp[last][first] = j;
      if (j == dim) {
        j = ps[j - 1];
      }
    }
  }
}

vector<vector<int>> dpst;
vector<vector<int>> dpts;
string s;
string t;

int get_longest(int last, int first, bool cs) {
  if (cs == 0) {
    if (!(0 <= last && last < (int) s.size() && 0 <= first && first < (int) t.size())) {
      return 0;
    }
    return dpst[last][first];
  } else {
    if (!(0 <= last && last < (int) t.size() && 0 <= first && first < (int) s.size())) {
      return 0;
    }
    return dpts[last][first];
  }
}

int main() {

  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 sol = -1, l, f, r;


  for (int rev_t = 0; rev_t <= 1; rev_t++) {
    int n = (int) s.size(), m = (int) t.size();
    dpst.resize(n, vector<int> (m));
    dpts.resize(m, vector<int> (n));
    compute(dpst, s, t);
    compute(dpts, t, s);
    for (int last_a = 0; last_a <= n - 2; last_a++) {
      {
        int cur =  dpst[last_a][0];
        if (cur > sol) {
          sol = cur;
          l = last_a;
          f = 0;
          r = rev_t;
        }
      }
      for (int first_a = 1; first_a < m; first_a++) {
        int cur = dpst[last_a][first_a] + dpts[first_a - 1][last_a + 1];
        if (cur > sol) {
          sol = cur;
          l = last_a;
          f = first_a;
          r = rev_t;
        }
      }
    }
    {
      for (int first_a = 0; first_a < m; first_a++) {
        int cur =  dpst[n - 1][first_a];
        if (cur > sol) {
          sol = cur;
          l = n - 1;
          f = first_a;
          r = rev_t;
        }
      }
    }
    reverse(t.begin(), t.end());
  }

  if (r) {
    reverse(t.begin(), t.end());
  }
  int n = (int) s.size(), m = (int) t.size();
  dpst.resize(n, vector<int> (m));
  dpts.resize(m, vector<int> (n));
  compute(dpst, s, t);
  compute(dpts, t, s);
  int rev = r;
  int last_a = l;
  int first_a = f;
  int first_b = last_a + 1;
  int last_b = first_a - 1;
  int len_a = get_longest(last_a, first_a, 0);
  int len_b = get_longest(last_b, first_b, 1);
  /// [last_a - len_a]
  /// [last_b - len_b]

  int jump_a = last_a - len_a + 1;
  int jump_b;

  /// [a, b]
  ///        [b, a]

  if (rev == 0) {
    jump_b = last_b - len_b + 1;
  } else {
    jump_b = (int) t.size() - (first_a + len_a);
  }
  if (verbose) {
    cout << "\t\t\t\t\tcomps = " << comps << "\n";
  }
  cout << sol << "\n";
  cout << jump_a << " " << jump_b << "\n";
  return 0;
}

Compilation message

necklace.cpp: In function 'int main()':
necklace.cpp:81:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |     freopen ("___input___.txt", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
necklace.cpp:153:3: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
  153 |   if (rev == 0) {
      |   ^~
necklace.cpp:156:40: warning: 'f' may be used uninitialized in this function [-Wmaybe-uninitialized]
  156 |     jump_b = (int) t.size() - (first_a + len_a);
      |                               ~~~~~~~~~^~~~~~~~
necklace.cpp:147:23: warning: 'l' may be used uninitialized in this function [-Wmaybe-uninitialized]
  147 |   int jump_a = last_a - len_a + 1;
      |                ~~~~~~~^~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 7 ms 1620 KB Output is correct
7 Correct 6 ms 1620 KB Output is correct
8 Correct 6 ms 1412 KB Output is correct
9 Correct 6 ms 1564 KB Output is correct
10 Correct 6 ms 1620 KB Output is correct
11 Correct 5 ms 1492 KB Output is correct
12 Correct 5 ms 1492 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 7 ms 1620 KB Output is correct
7 Correct 6 ms 1620 KB Output is correct
8 Correct 6 ms 1412 KB Output is correct
9 Correct 6 ms 1564 KB Output is correct
10 Correct 6 ms 1620 KB Output is correct
11 Correct 5 ms 1492 KB Output is correct
12 Correct 5 ms 1492 KB Output is correct
13 Correct 775 ms 71032 KB Output is correct
14 Correct 721 ms 71036 KB Output is correct
15 Correct 718 ms 66880 KB Output is correct
16 Correct 700 ms 69868 KB Output is correct
17 Correct 658 ms 68468 KB Output is correct
18 Correct 663 ms 70500 KB Output is correct
19 Correct 656 ms 70448 KB Output is correct
20 Correct 683 ms 68508 KB Output is correct
21 Correct 711 ms 69284 KB Output is correct