Submission #251413

#	Time	Username	Problem	Language	Result	Execution time	Memory
251413		phuleethanh	Palindromes (APIO14_palindrome)	C++14	100 / 100	28 ms	35464 KiB

palindrome

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

void insert(int i)
{
    //Tim nut X to nhat thoa man
    while (i - Tree[last].len - 1 < 0 || s[i - Tree[last].len - 1] != s[i])
        last = Tree[last].suffLink;
    int w = s[i] - 'a';
    //Them moi : Neu nut nay chua co trong cay
    if (Tree[last].child[w] == 0)
    {
        //tim nut suffixLink tro toi
        int tmp = Tree[last].suffLink;
        while (i - Tree[tmp].len - 1 < 0 || s[i - Tree[tmp].len - 1] != s[i])
            tmp = Tree[tmp].suffLink;
        //tao nut moi va tro vao day
        Tree[last].child[w] = ++num, Tree[num].len = Tree[last].len + 2;
        Tree[num].suffLink = (Tree[num].len == 1 ? 0 : Tree[tmp].child[w]);
    }
    last = Tree[last].child[w];
    Tree[last].occ++;
}

int main()
{
    //freopen("z.inp", "r", stdin);
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    Tree[1].len = -1, Tree[0].suffLink = Tree[1].suffLink = 1;
    last = 0, num = 1;
    cin >> s;
    for (int i = 0; i < s.size(); i++)
        insert(i);
    long long ans = 0;
    for (int i = num; 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:39:23: 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