Submission #251401

#	Time	Username	Problem	Language	Result	Execution time	Memory
251401		phuleethanh	Palindromes (APIO14_palindrome)	C++14	47 / 100	1091 ms	8180 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;
const int N = 303030;
struct nut
{
    int len = 0, occ = 0, suffLink = 0, child[26];
};
vector<nut> Tree;
char s[N];
int last;

void initPalinTree()
{
    Tree.emplace_back(), Tree.emplace_back();
    Tree[1].len = -1, Tree[0].suffLink = Tree[1].suffLink = 1;
    last = 0;
}

bool insert(int i)
{
    //Tim nut X to nhat thoa man
    while (s[i - Tree[last].len - 1] != s[i])
        last = Tree[last].suffLink;
    //Tim nut ma suffLink se tro toi
    int w = s[i] - 'a', tmp = Tree[last].suffLink;
    while (s[i - Tree[tmp].len - 1] != s[i])
        tmp = Tree[tmp].suffLink;
    //Them moi : Neu nut nay chua co trong cay
    if (Tree[last].child[w] == 0)
    {
        Tree[last].child[w] = Tree.size();
        Tree.emplace_back();
        Tree.back().len = Tree[last].len + 2;
        Tree.back().suffLink = (Tree.back().len == 1 ? 0 : Tree[tmp].child[w]);
    }
    last = Tree[last].child[w];
    Tree[last].occ++;
    return 1;
}

int main()
{
    //freopen("z.inp", "r", stdin);
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    initPalinTree();
    cin >> s;
    for (int i = 0; i < strlen(s); i++)
        insert(i);
    long long ans = 0;
    for (int i = Tree.size() - 1; i >= 2; i--)
    {
        ans = max(ans, 1ll * Tree[i].len * Tree[i].occ);
        Tree[Tree[i].suffLink].occ += Tree[i].occ;
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:47:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < strlen(s); i++)
                     ~~^~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27