Submission #989711

#	Time	Username	Problem	Language	Result	Execution time	Memory
989711		steveonalex	Palindromic Partitions (CEOI17_palindromic)	C++17	100 / 100	180 ms	43692 KiB

palindromic

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }
 const long N = 1e6 + 69;
 const long MOD1 = 1e9 + 7, MOD2 = 1e9 + 9;
 const long BASE = 307;
  
 ll pow1[N], pow2[N];
 void prepare(){
     pow1[0] = pow2[0] = 1;
     for(long i = 1; i<N; ++i){
         pow1[i] = pow1[i-1] * BASE % MOD1;
         pow2[i] = pow2[i-1] * BASE % MOD2;
     }
 }
  
 struct Hash{
     long n;
     vector<ll> hash1, hash2;
  
     Hash(){}
  
     Hash(string s){
         n = s.size();
         hash1.resize(n+1), hash2.resize(n+1);
         for(long i = 1; i<=n; ++i){
             hash1[i] = (hash1[i-1] + s[i-1] * pow1[i-1]) % MOD1;
             hash2[i] = (hash2[i-1] + s[i-1] * pow2[i-1]) % MOD2;
         }
     }
  
     ll get1(long l, long r){
         return (hash1[r] - hash1[l - 1] + MOD1) * pow1[N - l] % MOD1;
     }
     ll get2(long l, long r){
         return (hash2[r] - hash2[l - 1] + MOD2) * pow2[N - l] % MOD2;
     }
     ll getCode(long l, long r){return get1(l, r) * MOD2 + get2(l, r);}
 };
 

int solve(){
    string s; cin >> s;
    int n = s.size();
    Hash x(s);

    int ans = 0;
    bool check = false;
    pair<int, int> last = {1, n};
    for(int i = 0; i<n/2; ++i){
        if (x.getCode(last.first, i+1) == x.getCode(n - i, last.second)){
            ans++;
            last.first = i + 2;
            last.second = n - i - 1;
            if ((i + 1) * 2 == n) check = true;
        }
    }
    if (check) return ans * 2;
    return ans * 2 + 1;
}
 
int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    prepare();

    int t; cin >> t; 
    while(t--) cout << solve() << "\n";
 
 
    return 0;
}

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