Submission #155122

#	Time	Username	Problem	Language	Result	Execution time	Memory
155122		lyc	Palindromic Partitions (CEOI17_palindromic)	C++14	100 / 100	86 ms	15072 KiB

palindromic

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

typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef pair<ii, int> ri3;
#define mp make_pair
#define pb push_back
#define fi first
#define sc second
#define SZ(x) (int)(x).size()
#define ALL(x) begin(x), end(x) 
#define REP(i, n) for (int i = 0; i < n; ++i) 
#define FOR(i, a, b) for (int i = a; i <= b; ++i)
#define RFOR(i, a, b) for (int i = a; i >= b; --i)

const int P = 1e9 + 11;
const int Q = 4001;
const int MAXN = 1e6+5;

int T, N;
string S;
int F[MAXN];

int solve(int s, int e) {
    //cout << "solve " << s << " " << e << endl;
    if (s > e) return 0;
    int h1 = 0, h2 = 0;
    for (int l = 0; s+l < e-l; ++l) {
        h1 = (((ll)h1 * Q % P) + (S[s+l]-'a')) % P;
        h2 = ((ll)h2 + (((ll)(S[e-l]-'a')*F[l]) % P)) % P;
        if (h1 == h2) return solve(s+l+1, e-l-1) + 2;
    }
    return 1;
}

int main() {
    //freopen("in.txt", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(0);

    F[0] = 1;
    FOR(i,1,MAXN-1) F[i] = (ll)F[i-1] * Q % P;

    cin >> T;
    while(T--){
        cin >> S;
        N = S.length();
        cout << solve(0,N-1) << '\n';
    }
}

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