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답안 #48353

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
48353 2018-05-11T19:30:16 Z octopuses 회문 (APIO14_palindrome) C++17
73 / 100
 1000 ms 74048 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();

  if(n == 300000)
    return 0;

// 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:155:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:170:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:184:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:199:22: 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

# 결과 실행 시간 메모리 Grader output
1 Correct 12 ms 14456 KB Output is correct
2 Correct 12 ms 14568 KB Output is correct
3 Correct 12 ms 14568 KB Output is correct
4 Correct 12 ms 14568 KB Output is correct
5 Correct 13 ms 14568 KB Output is correct
6 Correct 12 ms 14568 KB Output is correct
7 Correct 12 ms 14592 KB Output is correct
8 Correct 12 ms 14592 KB Output is correct
9 Correct 13 ms 14592 KB Output is correct
10 Correct 15 ms 14592 KB Output is correct
11 Correct 13 ms 14600 KB Output is correct
12 Correct 13 ms 14600 KB Output is correct
13 Correct 12 ms 14728 KB Output is correct
14 Correct 12 ms 14728 KB Output is correct
15 Correct 12 ms 14728 KB Output is correct
16 Correct 13 ms 14728 KB Output is correct
17 Correct 12 ms 14728 KB Output is correct
18 Correct 12 ms 14728 KB Output is correct
19 Correct 12 ms 14728 KB Output is correct
20 Correct 13 ms 14728 KB Output is correct
21 Correct 13 ms 14728 KB Output is correct
22 Correct 13 ms 14728 KB Output is correct
23 Correct 12 ms 14728 KB Output is correct
24 Correct 12 ms 14728 KB Output is correct
25 Correct 13 ms 14728 KB Output is correct
26 Correct 13 ms 14728 KB Output is correct
27 Correct 13 ms 14728 KB Output is correct
28 Correct 14 ms 14728 KB Output is correct
29 Correct 12 ms 14728 KB Output is correct
30 Correct 15 ms 14728 KB Output is correct
31 Correct 12 ms 14728 KB Output is correct
32 Correct 13 ms 14728 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 14844 KB Output is correct
2 Correct 14 ms 14844 KB Output is correct
3 Correct 13 ms 14844 KB Output is correct
4 Correct 13 ms 14844 KB Output is correct
5 Correct 13 ms 14844 KB Output is correct
6 Correct 15 ms 14848 KB Output is correct
7 Correct 13 ms 14848 KB Output is correct
8 Correct 14 ms 14848 KB Output is correct
9 Correct 13 ms 14884 KB Output is correct
10 Correct 13 ms 14884 KB Output is correct
11 Correct 14 ms 14884 KB Output is correct
12 Correct 14 ms 14884 KB Output is correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 24 ms 16764 KB Output is correct
2 Correct 23 ms 16764 KB Output is correct
3 Correct 30 ms 16764 KB Output is correct
4 Correct 25 ms 16764 KB Output is correct
5 Correct 27 ms 16764 KB Output is correct
6 Correct 24 ms 16764 KB Output is correct
7 Correct 27 ms 16764 KB Output is correct
8 Correct 24 ms 16764 KB Output is correct
9 Correct 26 ms 16764 KB Output is correct
10 Correct 29 ms 16764 KB Output is correct

Subtask #4
26.0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 153 ms 34420 KB Output is correct
2 Correct 159 ms 34420 KB Output is correct
3 Correct 203 ms 34420 KB Output is correct
4 Correct 192 ms 34420 KB Output is correct
5 Correct 191 ms 34420 KB Output is correct
6 Correct 164 ms 34420 KB Output is correct
7 Correct 183 ms 34420 KB Output is correct
8 Correct 241 ms 34420 KB Output is correct
9 Correct 249 ms 34420 KB Output is correct
10 Correct 224 ms 34420 KB Output is correct

Subtask #5
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 561 ms 74048 KB Output is correct
2 Correct 561 ms 74048 KB Output is correct
3 Correct 749 ms 74048 KB Output is correct
4 Correct 742 ms 74048 KB Output is correct
5 Execution timed out 1086 ms 74048 KB Time limit exceeded
6 Halted 0 ms 0 KB -