oj.uz

Submission #48352

# Submission time Handle Problem Language Result Execution time Memory
48352 2018-05-11T19:21:15 Z octopuses Palindromes (APIO14_palindrome) C++17
73 / 100
 1000 ms 74032 KB 
#include <bits/stdc++.h>

#define ll long long
#define fr first
#define sc second
#define M (ll)(3e17)

using namespace std;
const int N = 300020;

char tmp[N];
int n;
ll answer, ans;
int Suf[N][20], c[N], d[N], temp[N], cnt[N];
int A[N], B[N];
int P[N], C[N];
set < int > S;
set < int>::iterator it;
string a;
vector < int > G[N];
vector < pair < int, int > > g[N];

int Parent(int v)
{
  if(P[v] == v)
    return v;
  return P[v] = Parent(P[v]);
}

inline void DSU(int v, int u)
{
  v = Parent(v);
  u = Parent(u);
  if(v == u)
    return;
  C[v] += C[u];
  P[u] = v;
  ans = max(ans, C[v] * 1ll);
}

inline int fnd(int mn, int v, int u)
{
  int s = 0;
  for(int k = 18; k >= 0; -- k)
    if(Suf[u][k] == Suf[v][k])
    {
      u += (1 << k);
      v += (1 << k);
      s += (1 << k);
    }
  s = min(mn, s);
  return s;
}

void sufsort()
{
  Suf[n + 1][0] = 0;
  int tot = 1;
  for(char ch = 'a'; ch <= 'z'; ++ ch)
    for(int i = 1; i <= n; ++ i)
      if(a[i] == ch)
        d[tot ++] = i;
  tot = 0;
  for(int i = 1; i <= n; ++ i)
  {
    if(a[d[i]] != a[d[i - 1]])
      tot ++;
    Suf[d[i]][0] = tot;
  }
  d[0] = n + 1;
  for(int i = 0; i <= n; ++ i)
    c[i] = d[i];
  for(int k = 1; k < 19; ++ k)
  {
    for(int i = 0; i <= n; ++ i)
      cnt[i] = 0;
    for(int i = 1; i <= n + 1; ++ i)
      cnt[Suf[i][k - 1]] ++;
    for(int i = 1; i <= n; ++ i)
      cnt[i] += cnt[i - 1];
    for(int i = n; i >= 0; -- i)
    {
      if(d[i] <= (1 << (k - 1)))
        continue;
      int j = d[i] - (1 << (k - 1));
      c[cnt[Suf[j][k - 1]] - 1] = j;
      cnt[Suf[j][k - 1]] --;
    }
    tot = 0;
    Suf[n + 1][k] = 0;
    for(int i = 1; i <= n; ++ i)
    {
      d[i] = c[i];
      if(Suf[c[i]][k - 1] != Suf[c[i - 1]][k - 1] || (c[i - 1] + (1 << (k - 1)) > n + 1) || Suf[c[i] + (1 << (k - 1))][k - 1] != Suf[c[i - 1] + (1 << (k - 1))][k - 1])
        tot ++;
      Suf[c[i]][k] = tot;
    }
  }
  for(int i = 1; i <= n; ++ i)
    c[d[i]] = i;
}

void palindrome()
{
  A[1] = 1;
  int r = 1;
  int l = 1;
  for(int i = 2; i <= n; ++ i)
  {
    A[i] = 1;
    if(r >= i)
      A[i] = min(A[l + r - i], r - i + 1);
    while(i + A[i] <= n && i - A[i] > 0 && a[i - A[i]] == a[i + A[i]])
      A[i] ++;
    if(i + A[i] - 1 > r)
      r = i + A[i] - 1, l = i - A[i] + 1;
  }
  B[1] = 0;
  l = r = 1;
  for(int i = 1; i <= n; ++ i)
  {
    B[i] = 0;
    if(r >= i)
      B[i] = min(B[l + r - i + 1], r - i + 1);
    while(i + B[i] <= n && i - B[i] - 1 > 0 && a[i + B[i]] == a[i - B[i] - 1])
      B[i] ++;
    if(i + B[i] - 1 > r)
      r = i + B[i] - 1, l = i - B[i];
  }
}

int main()
{
  char tmp;
  a = '#';
  tmp = getchar();
  while(tmp <= 'z' && tmp >= 'a')
    a += tmp, tmp = getchar(), n ++;
  a += char('a' - 1);
  sufsort();
  palindrome();

// Odd Palindromes

  for(int i = 1; i <= n; ++ i)
    P[i] = i, C[i] = 0;
  for(int i = 1; i <= n; ++ i)
    G[A[i]].push_back(i);
  ans = 0;
  for(int k = n; k >= 1; -- k)
  {
    for(int i = 0; i < G[k].size(); ++ i)
    {
      int v = G[k][i];
      it = S.lower_bound(c[v]);
      if(it != S.end())
        g[fnd(k, v, d[(*it)])].push_back({v, d[(*it)]});
      if(it != S.begin())
      {
        it --;
        g[fnd(k, v, d[(*it)])].push_back({v, d[(*it)]});
      }
      S.insert(c[v]);
      C[v] = 1;
      ans = max(ans, 1ll);
    }
    for(int i = 0; i < g[k].size(); ++ i)
      DSU(g[k][i].first, g[k][i].second);
    answer = max(answer, ans * (2 * k - 1ll));
  }
//  Even Palindromes

  for(int i = 1; i <= n; ++ i)
    P[i] = i, C[i] = 0, G[i].clear(), g[i].clear();
  for(int i = 1; i <= n; ++ i)
    G[B[i]].push_back(i);
  S.clear();
  ans = 0;
  for(int k = n; k >= 1; -- k)
  {
    for(int i = 0; i < G[k].size(); ++ i)
    {
      int v = G[k][i];
      it = S.lower_bound(c[v]);
      if(it != S.end())
        g[fnd(k, v, d[(*it)])].push_back({v, d[(*it)]});
      if(it != S.begin())
      {
        it --;
        g[fnd(k, v, d[(*it)])].push_back({v, d[(*it)]});
      }
      S.insert(c[v]);
      C[v] = 1;
      ans = max(ans, 1ll);
    }
    for(int i = 0; i < g[k].size(); ++ i)
      DSU(g[k][i].first, g[k][i].second);
    answer = max(answer, ans * (2ll * k));
  }
  cout << answer;
}

Compilation message

palindrome.cpp: In function 'int main()':
palindrome.cpp:152:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:167:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:181:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:196:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 14456 KB Output is correct
2 Correct 12 ms 14624 KB Output is correct
3 Correct 13 ms 14624 KB Output is correct
4 Correct 13 ms 14624 KB Output is correct
5 Correct 12 ms 14624 KB Output is correct
6 Correct 12 ms 14724 KB Output is correct
7 Correct 12 ms 14724 KB Output is correct
8 Correct 12 ms 14724 KB Output is correct
9 Correct 12 ms 14724 KB Output is correct
10 Correct 12 ms 14724 KB Output is correct
11 Correct 12 ms 14724 KB Output is correct
12 Correct 12 ms 14724 KB Output is correct
13 Correct 12 ms 14724 KB Output is correct
14 Correct 12 ms 14736 KB Output is correct
15 Correct 12 ms 14736 KB Output is correct
16 Correct 12 ms 14736 KB Output is correct
17 Correct 12 ms 14736 KB Output is correct
18 Correct 12 ms 14820 KB Output is correct
19 Correct 12 ms 14820 KB Output is correct
20 Correct 12 ms 14820 KB Output is correct
21 Correct 12 ms 14820 KB Output is correct
22 Correct 12 ms 14820 KB Output is correct
23 Correct 12 ms 14820 KB Output is correct
24 Correct 12 ms 14820 KB Output is correct
25 Correct 12 ms 14820 KB Output is correct
26 Correct 12 ms 14820 KB Output is correct
27 Correct 12 ms 14820 KB Output is correct
28 Correct 11 ms 14820 KB Output is correct
29 Correct 12 ms 14828 KB Output is correct
30 Correct 12 ms 14828 KB Output is correct
31 Correct 12 ms 14828 KB Output is correct
32 Correct 12 ms 14828 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 14844 KB Output is correct
2 Correct 13 ms 14844 KB Output is correct
3 Correct 13 ms 14972 KB Output is correct
4 Correct 13 ms 14972 KB Output is correct
5 Correct 13 ms 14972 KB Output is correct
6 Correct 13 ms 14972 KB Output is correct
7 Correct 14 ms 14972 KB Output is correct
8 Correct 13 ms 14972 KB Output is correct
9 Correct 13 ms 14972 KB Output is correct
10 Correct 13 ms 14972 KB Output is correct
11 Correct 13 ms 14972 KB Output is correct
12 Correct 13 ms 14972 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 16764 KB Output is correct
2 Correct 23 ms 16764 KB Output is correct
3 Correct 26 ms 16764 KB Output is correct
4 Correct 25 ms 16764 KB Output is correct
5 Correct 24 ms 16764 KB Output is correct
6 Correct 25 ms 16764 KB Output is correct
7 Correct 23 ms 16764 KB Output is correct
8 Correct 25 ms 16764 KB Output is correct
9 Correct 25 ms 16764 KB Output is correct
10 Correct 26 ms 16764 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 153 ms 34420 KB Output is correct
2 Correct 144 ms 34420 KB Output is correct
3 Correct 194 ms 34420 KB Output is correct
4 Correct 188 ms 34420 KB Output is correct
5 Correct 183 ms 34420 KB Output is correct
6 Correct 162 ms 34420 KB Output is correct
7 Correct 179 ms 34420 KB Output is correct
8 Correct 216 ms 34420 KB Output is correct
9 Correct 204 ms 34420 KB Output is correct
10 Correct 212 ms 34420 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 558 ms 74032 KB Output is correct
2 Correct 551 ms 74032 KB Output is correct
3 Correct 722 ms 74032 KB Output is correct
4 Correct 696 ms 74032 KB Output is correct
5 Execution timed out 1086 ms 74032 KB Time limit exceeded
6 Halted 0 ms 0 KB -