Submission #585621

#	Time	Username	Problem	Language	Result	Execution time	Memory
585621		amunduzbaev	Palindromic Partitions (CEOI17_palindromic)	C++17	0 / 100	0 ms	212 KiB

palindromic

#include "bits/stdc++.h"
using namespace std;
 
#define ar array
typedef int64_t ll;

const int N = 1e4 + 5;
const int P = 167;
const int mod = 1e9 + 7;

void solve(){
	string s; cin >> s;
	int n = s.size();
	s = "#" + s;
	int dp[n + 1] {}, h[n + 1] {}, pw[n + 1];
	pw[0] = 1;
	for(int i=1;i<=n;i++){
		h[i] = (h[i - 1] * 1ll * P + s[i] - 'a') % mod;
		pw[i] = pw[i-1] * 1ll * P % mod;
	}
	
	auto check = [&](int l, int r){
		return (h[r] - h[l] * 1ll * pw[r - l] % mod + mod) % mod == 
		(h[n - l] - h[n - r] * 1ll * pw[r - l] % mod + mod) % mod;
	};
	
	int res = 1;
	for(int i=0;i<=n/2;i++){
		for(int j=1;i + j<=n/2;j++){
			if(check(i, i + j) && (i ? dp[i] : true)){
				dp[i + j] = max(dp[i + j], dp[i] + 1);
			}
		}
		
		res = max(res, dp[i] * 2 + 1);
	}
	
	cout<<res<<"\n";
}

signed main(){
	ios::sync_with_stdio(0); cin.tie(0);
	
	int t; cin>>t;
	while(t--){
		solve();
	}
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 20
• Subtask 3: 0 / 25
• Subtask 4: 0 / 40