Submission #251390

#	Time	Username	Problem	Language	Result	Execution time	Memory
251390		phuleethanh	Palindromes (APIO14_palindrome)	C++14	100 / 100	39 ms	35080 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;
const int N = 303030;
int last, num, child[N][26], len[N], suffLink[N], occ[N];
string s;

void insert(int i)
{
    while (s[i - len[last] - 1] != s[i])
        last = suffLink[last];
    int w = s[i] - 'a', temp = suffLink[last];
    while (s[i - len[temp] - 1] != s[i])
        temp = suffLink[temp];
    if (child[last][w] == 0)
    {
        child[last][w] = ++num, len[num] = len[last] + 2;
        suffLink[num] = (len[num] == 1 ? 0 : child[temp][w]);
    }
    last = child[last][w], ++occ[last];
}

int main()
{
    //freopen("z.inp", "r", stdin);
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    len[0] = 0, len[1] = -1, last = num = 1, suffLink[0] = suffLink[1] = 1;
    cin >> s;
    for (int i = 0; i < s.size(); i++)
        insert(i);
    long long ans = 0;
    for (int i = num; i > 1; i--)
    {
        ans = max(ans, 1ll * len[i] * occ[i]);
        occ[suffLink[i]] += occ[i]; //cap nhat nguoc len cho cac nut suffLink
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:28:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); i++)
                     ~~^~~~~~~~~~

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