Submission #1062523

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062523		MladenP	Palindromes (APIO14_palindrome)	C++17	100 / 100	40 ms	64060 KiB

palindrome

#include <iostream>
#include <vector>
#define PRINT(x) cerr<<#x<<'='<<x<<endl;
using namespace std;

const int P_SIGMA = 26;
const int MINUS_NODE = 1;
const int ZERO_NODE = 2;

struct Node {
    int len, slink, cnt, dub;
    int to[P_SIGMA];
    Node(int _len = 0, int _slink = 0, int _cnt = 0, int _depth = 0) {
        len = _len; slink = _slink; cnt = _cnt; dub = _depth;
        for(int i = 0; i < P_SIGMA; i++) to[i] = 0;
    }
};

string s;
vector<Node> pt;
int suff;

void init() {
    suff = 2;
    s = "";
    pt.push_back(Node(0));
    pt.push_back(Node(-1, MINUS_NODE));
    pt.push_back(Node(0, MINUS_NODE));
}

int addLetter(char c) {
    s += c; 
    int cidx = c-'a';
    int len = s.size();
    while(c != s[len-2-pt[suff].len]) {
        suff = pt[suff].slink;
    }
    int nd = pt[suff].to[cidx];

    if(nd == 0) {
        nd = pt.size();
        pt[suff].to[cidx] = nd;
        pt.push_back(Node(pt[suff].len+2));
        if(suff == MINUS_NODE) {
            pt[nd].slink = ZERO_NODE;
        } else {
            int u = pt[suff].slink;
            while(c != s[len-2-pt[u].len]) {
                u = pt[u].slink;
            }
            pt[nd].slink = pt[u].to[cidx];
        }
        pt[nd].dub = pt[pt[nd].slink].dub+1;
    }
    pt[nd].cnt++;
    suff = nd;
    return pt[nd].dub;
}

void calcCnt() {
    for(int i = pt.size()-1; i > 2; i--) {
        pt[pt[i].slink].cnt += pt[i].cnt;
    }
}

int main() {
    ios::sync_with_stdio(false); cin.tie(0);
    string s; cin >> s;
    init();
    for(auto x : s) {
        addLetter(x);
    }
    calcCnt();
    long long rez = 0;
    for(int i = pt.size()-1; i > 2; i--) {
        rez = max(rez, (long long) pt[i].len*pt[i].cnt);
    }
    cout << rez << endl;
    return 0;
}

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