Submission #969458

#	Time	Username	Problem	Language	Result	Execution time	Memory
969458		_callmelucian	Palindromic Partitions (CEOI17_palindromic)	C++14	100 / 100	112 ms	28736 KiB

palindromic

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const ll base = 211;
const ll MOD = 1e9 + 21;
const int mn = 1e6 + 6;

ll pre[mn], basepow[mn];

ll getHash (int l, int r) {
    return (pre[r] - pre[l - 1] * basepow[r - l + 1] + MOD * MOD) % MOD;
}

void solve() {
    string s; cin >> s;
    int n = s.length();
    s = " " + s;

    for (int i = 1; i <= n; i++)
        pre[i] = (pre[i - 1] * base + s[i] - 'a' + 1) % MOD;

    int ans = 0;
    for (int r = n; n - r + 1 <= r;) {
        int l = n - r + 1, flg = 0;
        for (int k = 1; k < r - l + 1; k++) {
            if (getHash(l, l + k - 1) != getHash(r - k + 1, r)) continue;
            flg = 1, r -= k, ans += 2;
            break;
        }
        if (!flg) {
            ans++;
            break;
        }
    }
    cout << ans << "\n";
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    basepow[0] = 1;
    for (int i = 1; i < mn; i++)
        basepow[i] = basepow[i - 1] * base % MOD;

    int t; cin >> t;
    while (t--) solve();

    return 0;
}

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