Submission #848848

#	Time	Username	Problem	Language	Result	Execution time	Memory
848848		quanlt206	Palindromic Partitions (CEOI17_palindromic)	C++14	35 / 100	77 ms	4952 KiB

palindromic

#include<bits/stdc++.h>
#define X first
#define Y second
#define all(x) begin(x), end(x)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FORD(i, b, a) for(int i = (b); i >= (a); i--)
#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define mxx max_element
#define mnn min_element
#define SQR(x) (1LL * (x) * (x))
#define MASK(i) (1LL << (i))
#define Point Vector
#define left Left
#define right Right
#define div Div

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
typedef pair<db, db> pdb;
typedef pair<ld, ld> pld;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef pair<ll, ll> pll;
typedef pair<ll, pll> plll;
typedef pair<ll, int> pli;
typedef pair<ll, pii> plii;

template<class A, class B>
    bool maximize(A& x, B y) {
        if (x < y) return x = y, true; else return false;
    }
template<class A, class B>
    bool minimize(A& x, B y) {
        if (x > y) return x = y, true; else return false;
    }
/* END OF TEMPLATE */

const int N = 1e6 + 7;
const ll mod = 1e9 + 427;
const ll base = 311;

int dp[307][307], n;

ll h[N], p[N];

string s;

void buildHash() {
    p[0] = 1;
    h[0] = 0;
    FOR(i, 1, n) {
        p[i] = p[i - 1] * base % mod;
        h[i] = (h[i - 1] * base + s[i] - 'a' + 1) % mod;
    }
}

ll getHash(int i, int j) {
    return (h[j] - h[i - 1] * p[j - i + 1] + mod * mod) % mod;
}

void solve() {
    cin>>s;
    n = s.size();
    s = " " + s;
    buildHash();
    FORD(i, n, 1)
        FOR(j, i, n) {
            dp[i][j] = 1;
            FOR(k, 1, j - i + 1)
                if (i + k - 1 < j - k + 1) {
                    if (getHash(i, i + k - 1) == getHash(j - k + 1, j)) maximize(dp[i][j], 2 + dp[i + k][j - k]);
                }
                else break;
        }
    cout<<dp[1][n]<<"\n";
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int q;
    cin>>q;
    while (q--) solve();
    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 0 / 25
• Subtask 4: 0 / 40