제출 #681744

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
681744		vjudge1	회문 (APIO14_palindrome)	C++14	23 / 100	1092 ms	81484 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;

#define F first
#define S second
#define pb push_back
#define all(a) a.begin(), a.end()

typedef long long ll;
typedef pair<int, int> ii;

const int N = 10000 + 5;
const int mod = 1e9 + 7;

bool dp[N][N];
string s;
int n, P[N], H[N];
unordered_map<int, int> mp;

int Hash(int l, int r)
{
    return (H[r] - 1ll * H[l - 1] * P[r - l + 1] + 1ll * mod * mod) % mod;
}

void build()
{
    for(int i = 1; i <= n; i++)
        H[i] = (1ll * H[i - 1] * P[1] + (s[i] - 'a' + 1)) % mod;
}

void solve()
{
    cin >> s;
    n = s.size();
    s = " " + s;
    
    P[1] = 431;
    for(int i = 2; i <= n; i++) 
        P[i] = 1ll * P[i - 1] * P[1] % mod;
    build();
    
    for(int j = 1; j <= n; j++)
        for(int i = j; i >= 1; i--) if(s[i] == s[j])
            dp[i][j] = (i == j || i + 1 == j || dp[i + 1][j - 1]);
    
    int res = 0;
    for(int i = 1; i <= n; i++)
        for(int j = i; j <= n; j++)
            if(dp[i][j]) res = max(res, mp[Hash(i, j)] += (j - i + 1));
    cout << res;
}

signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    int t = 1;
    // cin >> t;
    while(t--) solve();
    return 0;
}

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