Submission #868894

#	Time	Username	Problem	Language	Result	Execution time	Memory
868894		sleepntsheep	회문 (APIO14_palindrome)	C++17	100 / 100	18 ms	34908 KiB

palindrome

#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>

using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
using ll = long long;
#define N 300005

char s[N]; 
int lz[N], len[N], link[N], nxt[N][26], n = 2, t = 2;
ll ans;

void init()
{
    n = t = 2;
    len[1] = -1, link[1] = 1;
    len[2] = 0, link[2] = 1;
}

void append(int pos)
{
    int la, l, c = s[pos] - 'a';
    for (l = t; !(pos-1>=len[l] && s[pos-1-len[l]] == s[pos]); l = link[l]);
    if (nxt[l][c]) { ++lz[t = nxt[l][c]]; return; }

    t = ++n;
    len[n] = len[l] + 2;
    ++lz[n];
    nxt[l][c] = n;

    if (len[n] == 1)
    {
        link[n] = 2;
        return;
    }

    for (la = link[l]; !(pos-1>=len[la] && s[pos-1-len[la]] == s[pos]); la=link[la]);
    link[n] = nxt[la][c];
}

void pushlazy()
{
    for (int i = n; i >= 3; --i)
    {
        lz[link[i]] += lz[i];
        ans = max(ans, 1ll*lz[i]*len[i]);
    }
}


int main()
{
    ShinLena;
    cin >> s;
    init();
    for (int i = 0; s[i]; ++i) append(i);
    pushlazy();
    cout << ans;
    return 0;
}

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