제출 #156012

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
156012		xennygrimmato	회문 (APIO14_palindrome)	C++17	100 / 100	103 ms	40584 KiB

palindrome

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
 
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
 
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
 
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
 
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
 
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
 
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;
const int MAXN = 300002;
 
// Credit: benq's Palindromic Tree template

template<int SZ> struct palTree {
    static const int sigma = 26;
 
    int s[SZ], len[SZ], link[SZ], to[SZ][sigma], oc[SZ];
     
    int n, last, sz;
     
    palTree() {
        s[n++] = -1;
        link[0] = 1;
        len[1] = -1;
        sz = 2;
    }
     
    int get_link(int v) {
        while(s[n-len[v]-2] != s[n-1]) v = link[v];
        return v;
    }
     
    void add_letter(int c) {
        s[n++] = c;
        last = get_link(last);
        if (!to[last][c]) {
            len[sz] = len[last]+2;
            link[sz] = to[get_link(link[last])][c];
            to[last][c] = sz++;
        }
        last = to[last][c];
        oc[last] ++;
    }
    
    void prop() {
        vpi v;
        FOR(i,2,sz) v.pb({len[i],i});
        sort(all(v)); reverse(all(v));
        for (auto a: v) oc[link[a.s]] += oc[a.s]; 
    }
};

palTree<MAXN> p;

int main() {
    string s; cin >> s;
    for(char c: s) p.add_letter(c - 'a');
    p.prop();
    ll ret = 0;
    FOR(i, 2, p.sz) ret = max(ret, (ll)p.len[i] * p.oc[i]);
    cout << ret;
}

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