Submission #493519

#	Time	Username	Problem	Language	Result	Execution time	Memory
493519		JovanB	Palindromes (APIO14_palindrome)	C++17	100 / 100	28 ms	36620 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;

ll res = 0;

const int C = 1000000;

struct PTree{
    struct Node{
        int len, cnt, slink, dpt, to[26];
    } tree[C];
    int suf = 0;
    int idxx = 0;
    string s = "";
    void init(){
        tree[1].len = -1, tree[1].cnt = 0, tree[1].slink = 1, tree[1].dpt = 0;
        tree[2].len = 0, tree[2].cnt = 0, tree[2].slink = 1, tree[1].dpt = 0;
        suf = idxx = 2;
    }
    void addChar(char c){
        s += c;
        int n = s.size();
        while(n - 2 - tree[suf].len < 0 || s[n - 2 - tree[suf].len] != c) suf = tree[suf].slink;
        int node = tree[suf].to[c - 'a'];
        if(node == 0){
            node = ++idxx;
            tree[suf].to[c - 'a'] = idxx;
            tree[node].len = tree[suf].len + 2;
            if(suf == 1) tree[node].slink = 2;
            else{
                int v = tree[suf].slink;
                while(s[n - 2 - tree[v].len] != c) v = tree[v].slink;
                tree[node].slink = tree[v].to[c - 'a'];
            }
            tree[node].dpt = tree[tree[node].slink].dpt + 1;
        }
        tree[node].cnt++;
        suf = node;
    }
    void calc(){
        for(int node=idxx; node>=3; node--){
            res = max(res, 1LL*tree[node].len*tree[node].cnt);
            tree[tree[node].slink].cnt += tree[node].cnt;
        }
    }
} pal;

int main(){
    ios_base::sync_with_stdio(false), cin.tie(0);
    cout.precision(10);
    cout << fixed;

    string s;
    cin >> s;
    pal.init();
    for(auto c : s) pal.addChar(c);
    pal.calc();
    cout << res << "\n";
    return 0;
}

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