oj.uz

답안 #48360

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
48360 2018-05-11T20:10:42 Z octopuses 회문 (APIO14_palindrome) C++17
58 / 100
 1000 ms 56972 KB 
#include <bits/stdc++.h>
#pragma GCC optimize("O3")

#define ll long long
#define fr first
#define sc second
#define M (ll)(3e17)
#define MAX(a,b) (a>b?a:b)

using namespace std;
const int N = 300020;

char tmp[N];
int n;
ll answer, ans;
int Suf[N][20], c[N], d[N], cnt[N];
int A[N], B[N];
int P[N];
int L[N], R[N], F[N];
string a;
vector < int > G[N];
vector < pair < int, int > > g[N];

inline int get(int x)
{
  int s = 0;
  while(x > 0)
  {
    s = max(s, F[x]);
    x -= x & (-x);
  }
  return s;
}
inline void upd(int x, int v)
{
  while(x <= n)
  {
    F[x] = MAX(F[x], v);
    x += x & (-x);
  }
}

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;
  cnt[v] += cnt[u];
  P[u] = v;
  ans = MAX(ans, cnt[v] * 1ll);
}

inline void fnd(int mn, int v, int u)
{
  int s = 0, x = v, y = u;
  for(int k = 18; k >= 0; -- k)
    if(Suf[u][k] == Suf[v][k])
    {
      u += (1 << k);
      v += (1 << k);
      s += (1 << k);
    }
  if(s >= mn)
    DSU(x, y);
  else
    g[s].push_back({x, y});
}

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, cnt[i] = 1;
  for(int i = 1; i <= n; ++ i)
    G[A[i]].push_back(i);
  ans = 0;
  R[0] = n + 1;
  L[n + 1] = 0;
  for(int k = n / 2 + 1; k >= 1; -- k)
  {
    for(int i = 0; i < G[k].size(); ++ i)
    {
      int v = G[k][i];
      int x = get(c[v]);
      if(x != 0)
        fnd(k, d[x], v);
      int y = R[x];
      R[x] = c[v];
      L[c[v]] = x;
      if(y != n + 1)
        fnd(k, d[y], v);
      R[c[v]] = y;
      L[y] = c[v];
      upd(c[v], c[v]);
      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, cnt[i] = 1, G[i].clear(), g[i].clear(), F[i] = 0;
  for(int i = 1; i <= n; ++ i)
    G[B[i]].push_back(i);
  ans = 0;
  L[n + 1] = 0; R[0] = n + 1; F[0] = 0;
  for(int k = n / 2; k >= 1; -- k)
  {
    for(int i = 0; i < G[k].size(); ++ i)
    {
      int v = G[k][i];
      int x = get(c[v]);
      if(x != 0)
        fnd(k, d[x], v);
      int y = R[x];
      R[x] = c[v];
      L[c[v]] = x;
      if(y != n + 1)
        fnd(k, d[y], v);
      R[c[v]] = y;
      L[y] = c[v];
      upd(c[v], c[v]);
    }
    for(int i = 0; i < g[k].size(); ++ i)
      DSU(g[k][i].first, g[k][i].second);
    answer = MAX(answer, ans * (2ll * k));
  }
  printf("%lld\n", answer);
}

Compilation message

palindrome.cpp: In function 'int main()':
palindrome.cpp:176:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:192:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:207:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:222:22: 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 15 ms 14568 KB Output is correct
5 Correct 12 ms 14696 KB Output is correct
6 Correct 12 ms 14696 KB Output is correct
7 Correct 12 ms 14768 KB Output is correct
8 Correct 12 ms 14768 KB Output is correct
9 Correct 12 ms 14768 KB Output is correct
10 Correct 12 ms 14768 KB Output is correct
11 Correct 12 ms 14768 KB Output is correct
12 Correct 12 ms 14768 KB Output is correct
13 Correct 12 ms 14768 KB Output is correct
14 Correct 12 ms 14768 KB Output is correct
15 Correct 13 ms 14824 KB Output is correct
16 Correct 12 ms 14824 KB Output is correct
17 Correct 12 ms 14824 KB Output is correct
18 Correct 12 ms 14824 KB Output is correct
19 Correct 13 ms 14824 KB Output is correct
20 Correct 12 ms 14824 KB Output is correct
21 Correct 12 ms 14824 KB Output is correct
22 Correct 12 ms 14824 KB Output is correct
23 Correct 13 ms 14824 KB Output is correct
24 Correct 13 ms 14824 KB Output is correct
25 Correct 12 ms 14824 KB Output is correct
26 Correct 12 ms 14824 KB Output is correct
27 Correct 12 ms 14824 KB Output is correct
28 Correct 12 ms 14824 KB Output is correct
29 Correct 12 ms 14824 KB Output is correct
30 Correct 12 ms 14824 KB Output is correct
31 Correct 12 ms 14824 KB Output is correct
32 Correct 12 ms 14824 KB Output is correct

Subtask #2
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 14844 KB Output is correct
2 Correct 13 ms 14848 KB Output is correct
3 Correct 13 ms 14848 KB Output is correct
4 Correct 13 ms 14848 KB Output is correct
5 Correct 13 ms 14892 KB Output is correct
6 Correct 13 ms 14892 KB Output is correct
7 Correct 13 ms 14892 KB Output is correct
8 Correct 13 ms 14892 KB Output is correct
9 Correct 13 ms 14892 KB Output is correct
10 Correct 13 ms 14892 KB Output is correct
11 Correct 13 ms 14900 KB Output is correct
12 Incorrect 13 ms 14900 KB Output isn't correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 16180 KB Output is correct
2 Correct 19 ms 16180 KB Output is correct
3 Correct 19 ms 16180 KB Output is correct
4 Correct 19 ms 16180 KB Output is correct
5 Correct 20 ms 16180 KB Output is correct
6 Correct 20 ms 16180 KB Output is correct
7 Correct 19 ms 16180 KB Output is correct
8 Correct 21 ms 16180 KB Output is correct
9 Correct 20 ms 16180 KB Output is correct
10 Correct 20 ms 16180 KB Output is correct

Subtask #4
26.0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 82 ms 28968 KB Output is correct
2 Correct 85 ms 28968 KB Output is correct
3 Correct 90 ms 28968 KB Output is correct
4 Correct 106 ms 28968 KB Output is correct
5 Correct 120 ms 28968 KB Output is correct
6 Correct 101 ms 28968 KB Output is correct
7 Correct 135 ms 28968 KB Output is correct
8 Correct 128 ms 28968 KB Output is correct
9 Correct 125 ms 28968 KB Output is correct
10 Correct 135 ms 28968 KB Output is correct

Subtask #5
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 393 ms 56972 KB Output is correct
2 Correct 365 ms 56972 KB Output is correct
3 Correct 326 ms 56972 KB Output is correct
4 Correct 351 ms 56972 KB Output is correct
5 Correct 831 ms 56972 KB Output is correct
6 Correct 414 ms 56972 KB Output is correct
7 Correct 505 ms 56972 KB Output is correct
8 Execution timed out 1027 ms 56972 KB Time limit exceeded
9 Halted 0 ms 0 KB -