제출 #1311404

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1311404		zbyszko	Palindromic Partitions (CEOI17_palindromic)	C++20	100 / 100	151 ms	19636 KiB

palindromic

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

using ull = unsigned long long;
using ll = long long;
using pii = pair<ll,ll>;
#define x first
#define y second

ll p=31;
ll mod=1000000007;
ll ppow[1000001];

void puz(){
    ppow[0]=1;
    for(int i=1;i<=1000000;i++){
        ppow[i]=(ppow[i-1]*p)%mod;
    }
    return;
}

void has(vector<ll>& has,string s){
    has[0]=0;
    for(int i=1;i<=s.size();i++){
        has[i]=(has[i-1]+((s[i-1]-'a'+1)*ppow[i-1]))%mod;
    }
    return;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int t;cin >> t;
    puz();
    while(t--){
        string s;cin >> s;
        ll n=s.size();
        vector<ll> hash(n+1);
        has(hash,s);
        ll l=0,ans=0;
        for(ll i=0;i<n;i++){
            //cout << l << " " << i << endl;
            if(i>=(n)/2){
                if(n%2==0){
                    if(l!=i) ans++;
                    break;
                }
                else{
                    ans++;
                    break;
                }
            }
            ll h1=(hash[i+1]-hash[l]+mod)%mod;
            ll h2=(hash[n-l]-hash[n-1-i]+mod)%mod;
            
            if((h1*ppow[n-1-i])%mod==(h2*ppow[l])%mod){
                ans+=2;
                l=i+1;
                //cout << ans << endl;
            }
        }
        cout << ans << endl;
    }    
    return 0;
}

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