Submission #1085050

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085050		Aliyyiakbar	Palindromes (APIO14_palindrome)	C++17	100 / 100	36 ms	69600 KiB

palindrome

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/hash_policy.hpp>
#include <ext/pb_ds/hash_policy.hpp>

#define int long long
#define $AzH_TxdmN$ ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")

#define ep emplace_back
#define pb push_back
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()

using namespace std;
using namespace __gnu_pbds;

template <typename T>
using __indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using __indexed_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int sz = 3e5+9;
const int LOG = 65;
const int MOD = 1e9+7;
const int INF = 1e18;

struct PT
{
    struct Node
    {
        int next[26], link, len;
        int occ;
    };
    string s;
    vector<Node> t;
    int siz, last, n;
    int res;
    PT(string& _s) : s(_s), n(_s.size()), res(0)
    {
        t.resize(n + 3);
        t[0].len = -1;
        t[1].len = 0;
        t[0].link = t[1].link = 0;
        siz = 2, last = 1;
        for (int i = 0; i <= n; ++i)
        {
            for (int j = 0; j < 26; ++j)
            {
                t[i].next[j] = -1;
            }
        }
    }
    void extend(int i)
    {
        int cur = last, cur_len = 0, letter = s[i] - 'a';
        while (true)
        {
            cur_len = t[cur].len;
            if (i - cur_len - 1 >= 0 && s[i] == s[i - cur_len - 1])
            {
                break;
            }
            cur = t[cur].link;
        }
        if (t[cur].next[letter] != -1)
        {
            last = t[cur].next[letter];
            t[last].occ++;
            return;
        }
        last = siz++;
        t[last].len = t[cur].len + 2;
        t[last].occ = 1;
        t[cur].next[letter] = last;
        if (t[last].len == 1)
        {
            t[last].link = 1;
        }
        else
        {
            while (true)
            {
                cur = t[cur].link;
                cur_len = t[cur].len;
                if (i - cur_len - 1 >= 0 && s[i] == s[i - cur_len - 1])
                {
                    t[last].link = t[cur].next[letter];
                    break;
                }
            }
        }
    }
    void build()
    {
        for (int i = siz - 1; i >= 2; --i)
        {
            t[t[i].link].occ += t[i].occ;
        }
    }
    void calllc()
    {
        for (int i = 2; i < siz; ++i)
        {
            res = max(res,t[i].len*t[i].occ);
        }
    }
};

string s;

void solve()
{
    cin>>s;
    PT pt(s);
    for (int i = 0; i < (int)s.length(); ++i)
    {
        pt.extend(i);
    }
    pt.build();
    pt.calllc();
    cout<<pt.res<<'\n';
}

signed main()
{
    $AzH_TxdmN$
    int t = 1;
    //cin >> t;
    while (t--)
    {
        solve();
    }
}

• Subtask 1: 8 / 8
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 26 / 26
• Subtask 5: 27 / 27