oj.uz

답안 #48361

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
48361 2018-05-11T20:17:59 Z octopuses 회문 (APIO14_palindrome) C++17
58 / 100
 1000 ms 56872 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;

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];
int S, X, Y;

inline int get(int x)
{
  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)
{
  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;
  int v, x, y;
  for(int k = n / 2 + 1; k >= 1; -- k)
  {
    for(int i = 0; i < G[k].size(); ++ i)
    {
      v = G[k][i];
      x = get(c[v]);
      if(x != 0)
        fnd(k, d[x], v);
      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)
    {
      v = G[k][i];
      x = get(c[v]);
      if(x != 0)
        fnd(k, d[x], v);
      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:177:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:193:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:208:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:223:22: 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 13 ms 14456 KB Output is correct
2 Correct 13 ms 14564 KB Output is correct
3 Correct 13 ms 14640 KB Output is correct
4 Correct 12 ms 14640 KB Output is correct
5 Correct 12 ms 14640 KB Output is correct
6 Correct 14 ms 14640 KB Output is correct
7 Correct 13 ms 14640 KB Output is correct
8 Correct 12 ms 14664 KB Output is correct
9 Correct 13 ms 14680 KB Output is correct
10 Correct 12 ms 14700 KB Output is correct
11 Correct 13 ms 14700 KB Output is correct
12 Correct 12 ms 14716 KB Output is correct
13 Correct 14 ms 14716 KB Output is correct
14 Correct 12 ms 14716 KB Output is correct
15 Correct 13 ms 14716 KB Output is correct
16 Correct 16 ms 14716 KB Output is correct
17 Correct 13 ms 14716 KB Output is correct
18 Correct 13 ms 14716 KB Output is correct
19 Correct 13 ms 14716 KB Output is correct
20 Correct 13 ms 14768 KB Output is correct
21 Correct 13 ms 14768 KB Output is correct
22 Correct 12 ms 14768 KB Output is correct
23 Correct 13 ms 14772 KB Output is correct
24 Correct 12 ms 14772 KB Output is correct
25 Correct 12 ms 14772 KB Output is correct
26 Correct 13 ms 14772 KB Output is correct
27 Correct 12 ms 14772 KB Output is correct
28 Correct 13 ms 14772 KB Output is correct
29 Correct 12 ms 14772 KB Output is correct
30 Correct 13 ms 14772 KB Output is correct
31 Correct 12 ms 14772 KB Output is correct
32 Correct 12 ms 14772 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 14 ms 14896 KB Output is correct
3 Correct 13 ms 14896 KB Output is correct
4 Correct 13 ms 14896 KB Output is correct
5 Correct 13 ms 14896 KB Output is correct
6 Correct 13 ms 14896 KB Output is correct
7 Correct 13 ms 14896 KB Output is correct
8 Correct 13 ms 14896 KB Output is correct
9 Correct 13 ms 14896 KB Output is correct
10 Correct 13 ms 14896 KB Output is correct
11 Correct 13 ms 14896 KB Output is correct
12 Incorrect 13 ms 14896 KB Output isn't correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 19 ms 16124 KB Output is correct
2 Correct 19 ms 16124 KB Output is correct
3 Correct 19 ms 16124 KB Output is correct
4 Correct 19 ms 16124 KB Output is correct
5 Correct 20 ms 16124 KB Output is correct
6 Correct 20 ms 16124 KB Output is correct
7 Correct 19 ms 16124 KB Output is correct
8 Correct 20 ms 16124 KB Output is correct
9 Correct 20 ms 16124 KB Output is correct
10 Correct 20 ms 16124 KB Output is correct

Subtask #4
26.0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 90 ms 28944 KB Output is correct
2 Correct 91 ms 28944 KB Output is correct
3 Correct 87 ms 28944 KB Output is correct
4 Correct 109 ms 28944 KB Output is correct
5 Correct 120 ms 28944 KB Output is correct
6 Correct 97 ms 28944 KB Output is correct
7 Correct 98 ms 28944 KB Output is correct
8 Correct 124 ms 28944 KB Output is correct
9 Correct 115 ms 28944 KB Output is correct
10 Correct 142 ms 28944 KB Output is correct

Subtask #5
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 332 ms 56872 KB Output is correct
2 Correct 317 ms 56872 KB Output is correct
3 Correct 296 ms 56872 KB Output is correct
4 Correct 378 ms 56872 KB Output is correct
5 Correct 750 ms 56872 KB Output is correct
6 Correct 384 ms 56872 KB Output is correct
7 Correct 456 ms 56872 KB Output is correct
8 Execution timed out 1080 ms 56872 KB Time limit exceeded
9 Halted 0 ms 0 KB -