Submission #1011325

#	Time	Username	Problem	Language	Result	Execution time	Memory
1011325		Irate	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	152 ms	19804 KiB

palindromic

#include<bits/stdc++.h>
using namespace std;
const int mxN = 1e6 + 6;
const int base = 53;
const int MOD = 1e9 + 7;
int H[mxN], P[mxN];
int get_hash(int l, int r){
    return (1LL * H[r] - 1LL * H[l - 1] * P[r - l + 1] % MOD + MOD) % MOD;
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    P[0] = 1;
    for(int i = 1;i < mxN;++i){
        P[i] = 1LL * P[i - 1] * base % MOD;
    }
    int t;
    cin >> t;
    while(t--){
        string str;
        cin >> str;
        int n = (int)str.size();
        str = '$' + str;
        for(int i = 1;i <= n;++i){
            H[i] = (1LL * H[i - 1] * base % MOD + (str[i] - 'a' + 1)) % MOD;
        }
        int L = 1;
        int res = 0;
        while(L <= n / 2){
            int p = L;
            while(p <= n / 2 && get_hash(L, p) != get_hash(n - p + 1, n - L + 1)){
                p++;
            }
            if(p > n / 2)break;
            res += 2;
            L = p + 1;
        }
        if(L <= n / 2 + n % 2)res++;
        cout << res << '\n';
    }
}

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