oj.uz

답안 #48356

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
48356 2018-05-11T19:50:06 Z octopuses 회문 (APIO14_palindrome) C++17
73 / 100
 1000 ms 63504 KB 
#include <bits/stdc++.h>

#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], temp[N], cnt[N];
int A[N], B[N];
int P[N], C[N];
int L[N], R[N], F[N];
string a;
vector < int > G[N];
vector < pair < int, int > > g[N];

int get(int x)
{
  int s = 0;
  while(x > 0)
  {
    s = max(s, F[x]);
    x -= x & (-x);
  }
  return s;
}
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;
  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);
    }
  return min(s, mn);
}

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] = 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)
        g[fnd(k, d[x], v)].push_back({d[x], v});
      int y = R[x];
      R[x] = c[v];
      L[c[v]] = x;
      if(y != n + 1)
        g[fnd(k, d[y], v)].push_back({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, C[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 + 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)
        g[fnd(k, d[x], v)].push_back({d[x], v});
      int y = R[x];
      R[x] = c[v];
      L[c[v]] = x;
      if(y != n + 1)
        g[fnd(k, d[y], v)].push_back({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 * (2ll * k));
  }
  cout << answer;
}

Compilation message

palindrome.cpp: In function 'int main()':
palindrome.cpp:172:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:188:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < g[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:202:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < G[k].size(); ++ i)
                    ~~^~~~~~~~~~~~~
palindrome.cpp:218:22: 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 14636 KB Output is correct
4 Correct 12 ms 14636 KB Output is correct
5 Correct 13 ms 14768 KB Output is correct
6 Correct 12 ms 14768 KB Output is correct
7 Correct 12 ms 14768 KB Output is correct
8 Correct 12 ms 14768 KB Output is correct
9 Correct 13 ms 14768 KB Output is correct
10 Correct 13 ms 14768 KB Output is correct
11 Correct 13 ms 14768 KB Output is correct
12 Correct 12 ms 14768 KB Output is correct
13 Correct 13 ms 14768 KB Output is correct
14 Correct 12 ms 14768 KB Output is correct
15 Correct 12 ms 14768 KB Output is correct
16 Correct 12 ms 14768 KB Output is correct
17 Correct 12 ms 14768 KB Output is correct
18 Correct 14 ms 14768 KB Output is correct
19 Correct 12 ms 14768 KB Output is correct
20 Correct 12 ms 14828 KB Output is correct
21 Correct 12 ms 14828 KB Output is correct
22 Correct 12 ms 14828 KB Output is correct
23 Correct 12 ms 14828 KB Output is correct
24 Correct 12 ms 14828 KB Output is correct
25 Correct 13 ms 14828 KB Output is correct
26 Correct 12 ms 14828 KB Output is correct
27 Correct 12 ms 14828 KB Output is correct
28 Correct 12 ms 14828 KB Output is correct
29 Correct 13 ms 14828 KB Output is correct
30 Correct 12 ms 14828 KB Output is correct
31 Correct 13 ms 14828 KB Output is correct
32 Correct 13 ms 14828 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 14 ms 14844 KB Output is correct
7 Correct 13 ms 14864 KB Output is correct
8 Correct 14 ms 14864 KB Output is correct
9 Correct 15 ms 14864 KB Output is correct
10 Correct 13 ms 14864 KB Output is correct
11 Correct 14 ms 14972 KB Output is correct
12 Correct 13 ms 14972 KB Output is correct

Subtask #3
24.0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 20 ms 16380 KB Output is correct
2 Correct 20 ms 16380 KB Output is correct
3 Correct 21 ms 16380 KB Output is correct
4 Correct 21 ms 16380 KB Output is correct
5 Correct 21 ms 16380 KB Output is correct
6 Correct 21 ms 16380 KB Output is correct
7 Correct 19 ms 16380 KB Output is correct
8 Correct 21 ms 16380 KB Output is correct
9 Correct 20 ms 16384 KB Output is correct
10 Correct 22 ms 16384 KB Output is correct

Subtask #4
26.0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 98 ms 30960 KB Output is correct
2 Correct 103 ms 30960 KB Output is correct
3 Correct 99 ms 30960 KB Output is correct
4 Correct 130 ms 30960 KB Output is correct
5 Correct 141 ms 30960 KB Output is correct
6 Correct 120 ms 30960 KB Output is correct
7 Correct 119 ms 30960 KB Output is correct
8 Correct 139 ms 30960 KB Output is correct
9 Correct 129 ms 30960 KB Output is correct
10 Correct 156 ms 30960 KB Output is correct

Subtask #5
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 377 ms 63504 KB Output is correct
2 Correct 338 ms 63504 KB Output is correct
3 Correct 349 ms 63504 KB Output is correct
4 Correct 445 ms 63504 KB Output is correct
5 Correct 959 ms 63504 KB Output is correct
6 Correct 521 ms 63504 KB Output is correct
7 Correct 544 ms 63504 KB Output is correct
8 Execution timed out 1091 ms 63504 KB Time limit exceeded
9 Halted 0 ms 0 KB -