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Submission #706062

# Submission time Handle Problem Language Result Execution time Memory
706062 2023-03-05T19:47:51 Z mahdi_hasnat Palindromes (APIO14_palindrome) C++17
100 / 100
 31 ms 41564 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#ifdef APURBA
#include "DEBUG_TEMPLATE.h"
#else
#define HERE
#define debug(args...)
#endif
typedef pair<int,int> pii;
#define ALL(x) x.begin(),x.end()

const int N = 3e5 +5;
const int oo = 1e9+7;


struct PalindromicTree {
 struct node {
  int nxt[26], len, st, en, link, diff, slink, cnt, oc;
 };
 string s;vector<node> t;
 int sz, last;
 PalindromicTree() {}
 PalindromicTree(string _s) {
  s = _s;
  int n = s.size();
  t.clear();
  t.resize(n + 9);sz = 2, last = 2;
  t[1].len = -1, t[1].link = 1;
  t[2].len = 0, t[2].link = 1;
  t[1].diff = t[2].diff = 0;
  t[1].slink = 1;t[2].slink = 2;
 }
 int extend(int pos) { // returns 1 if it creates a new palindrome
  int cur = last, curlen = 0;
  int ch = s[pos] - 'a';
  while (1) {curlen = t[cur].len;
   if (pos - 1 - curlen >= 0 && s[pos - 1 - curlen] == s[pos]) break;
   cur = t[cur].link;
  }
  if (t[cur].nxt[ch]) {last = t[cur].nxt[ch];
   t[last].oc++;
   return 0;
  }
  sz++;last = sz;
  t[sz].oc = 1;t[sz].len = t[cur].len + 2;
  t[cur].nxt[ch] = sz;t[sz].en = pos;
  t[sz].st = pos - t[sz].len + 1;
  if (t[sz].len == 1) {
   t[sz].link = 2;t[sz].cnt = 1;
   t[sz].diff = 1;t[sz].slink = 2;
   return 1;
  }
  while (1) {
   cur = t[cur].link;curlen = t[cur].len;
   if (pos - 1 - curlen >= 0 && s[pos - 1 - curlen] == s[pos]) {
    t[sz].link = t[cur].nxt[ch];
    break;
   }
  }
  t[sz].cnt = 1 + t[t[sz].link].cnt;
  t[sz].diff = t[sz].len - t[t[sz].link].len;
  if (t[sz].diff == t[t[sz].link].diff) t[sz].slink = t[t[sz].link].slink;
  else t[sz].slink = t[sz].link;
  return 1;
 }
 void calc_occurrences() {
  for (int i = sz; i >= 3; i--) t[t[i].link].oc += t[i].oc;
 }
 vector<array<int, 2>> minimum_partition() { //(even, odd), 1 indexed
  int n = s.size();
  vector<array<int, 2>> ans(n + 1, {0, 0}), series_ans(n + 5, {0, 0});
  ans[0][1] = series_ans[2][1] = 1e9;
  for (int i = 1; i <= n; i++) {
   extend(i - 1);
   for (int k = 0; k < 2; k++) {
    ans[i][k] = 1e9;
    for (int v = last; t[v].len > 0; v = t[v].slink) {
     series_ans[v][!k] = ans[i - (t[t[v].slink].len + t[v].diff)][!k];
     if (t[v].diff == t[t[v].link].diff) series_ans[v][!k] = min(series_ans[v][!k], series_ans[t[v].link][!k]);
     ans[i][k] = min(ans[i][k], series_ans[v][!k] + 1);
    }
   }
  }
  return ans;
 }
} t;

// int32_t main() {
//  string s;cin >> s;
//  PalindromicTree t(s);
//  for (int i = 0; i < s.size(); i++) t.extend(i);
//  t.calc_occurrences();
//  long long ans = 0;
//  for (int i = 3; i <= t.sz; i++) ans += t.t[i].oc;
//  cout << ans << '\n';
//  //auto ans = t.minimum_partition();
//  // for (int i = 1; i <= s.size(); i++) {
//  //   cout << (ans[i][1] == 1e9 ? -1 : ans[i][1]) << ' ';
//  //   cout << (ans[i][0] == 1e9 ? -2 : ans[i][0]) << '\n';
//  // }
// }


void solve()
{
	string s;
	cin>>s;
	PalindromicTree t(s);
	for(int i=0;i<s.size();i++)
	{
		t.extend(i);
	}
	t.calc_occurrences();
	ll ans = 0;
	for(int i=3;i<=t.sz;i++)
	{
		ans=max(ans, t.t[i].oc *1LL* t.t[i].len);
	}
	cout<<ans<<'\n';
}
/*

*/

int32_t main()
{
#ifndef APURBA
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
#endif
    int T=1;
    // cin>>T;
    while(T--)
    {
        solve();
    }
    return 0;
}

Compilation message

palindrome.cpp: In function 'void solve()':
palindrome.cpp:111:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 320 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 320 KB Output is correct
4 Correct 1 ms 316 KB Output is correct
5 Correct 0 ms 320 KB Output is correct
6 Correct 0 ms 324 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 0 ms 320 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 0 ms 340 KB Output is correct
22 Correct 0 ms 340 KB Output is correct
23 Correct 0 ms 340 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 0 ms 212 KB Output is correct
26 Correct 0 ms 340 KB Output is correct
27 Correct 0 ms 320 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 0 ms 320 KB Output is correct
31 Correct 1 ms 212 KB Output is correct
32 Correct 0 ms 212 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 448 KB Output is correct
2 Correct 0 ms 468 KB Output is correct
3 Correct 1 ms 452 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 440 KB Output is correct
7 Correct 0 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 444 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 0 ms 468 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1620 KB Output is correct
2 Correct 1 ms 1608 KB Output is correct
3 Correct 1 ms 1620 KB Output is correct
4 Correct 1 ms 1620 KB Output is correct
5 Correct 1 ms 1620 KB Output is correct
6 Correct 1 ms 1620 KB Output is correct
7 Correct 1 ms 1620 KB Output is correct
8 Correct 1 ms 1604 KB Output is correct
9 Correct 1 ms 1620 KB Output is correct
10 Correct 1 ms 1620 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 14036 KB Output is correct
2 Correct 10 ms 14036 KB Output is correct
3 Correct 11 ms 13936 KB Output is correct
4 Correct 11 ms 13992 KB Output is correct
5 Correct 11 ms 13984 KB Output is correct
6 Correct 9 ms 14036 KB Output is correct
7 Correct 12 ms 13996 KB Output is correct
8 Correct 8 ms 14036 KB Output is correct
9 Correct 8 ms 14032 KB Output is correct
10 Correct 9 ms 14028 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 41428 KB Output is correct
2 Correct 29 ms 41452 KB Output is correct
3 Correct 29 ms 41428 KB Output is correct
4 Correct 31 ms 41428 KB Output is correct
5 Correct 30 ms 41556 KB Output is correct
6 Correct 31 ms 41448 KB Output is correct
7 Correct 29 ms 41492 KB Output is correct
8 Correct 24 ms 41492 KB Output is correct
9 Correct 23 ms 41564 KB Output is correct
10 Correct 29 ms 41500 KB Output is correct
11 Correct 29 ms 41428 KB Output is correct
12 Correct 24 ms 41564 KB Output is correct