Submission #318646

#	Time	Username	Problem	Language	Result	Execution time	Memory
318646		Mahdi_Shokoufi	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	206 ms	28568 KiB

palindromic

//In The Name of Allah
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair < int , int > pii;
typedef pair < ll , ll > pll;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x.size())

const int N = 1e6 + 10;
const ll mod = 1000696969;
const ll inf = 1e18 + 10;

ll pw[N], hsh[N];

ll getHash(int l, int r){
    return (hsh[r] - hsh[l - 1] * pw[r - l + 1] % mod + mod) % mod;
}

void solve(){
    string s;
    cin >> s;
    for (int i = 1; i <= sz(s); i ++)
        hsh[i] = (hsh[i - 1] * 27LL % mod + (s[i - 1] - 'a' + 1)) % mod;
    int L = 1, R = sz(s), ans = 0;
    while (L <= R){
        int l = L, r = R, f = 0;
        while (l < r){
            if (getHash(L, l) == getHash(r, R)){
                l ++; r --;
                ans += 2;
                f = 1;
                break;
            }
            l ++; r --;
        }
        L = l; R = r;
        if (f == 0){
            ans ++;
            break;
        }
    }
    cout << ans << '\n';
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int q;
    cin >> q;
    pw[0] = 1;
    for (int i = 1; i < N; i ++)
        pw[i] = pw[i - 1] * 27LL % mod;
    while (q --)
        solve();
    return 0;
}

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