oj.uz

Submission #721377

# Submission time Handle Problem Language Result Execution time Memory
721377 2023-04-10T19:10:04 Z n0sk1ll Palindromes (APIO14_palindrome) C++14
23 / 100
 1000 ms 2524 KB 
#include <bits/stdc++.h>

#define FAST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0)
#define mp make_pair
#define xx first
#define yy second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define all(x) x.begin(),x.end()
#define ff(i,a,b) for (int i = a; i < b; i++)
#define fff(i,a,b) for (int i = a; i <= b; i++)
#define bff(i,a,b) for (int i = b-1; i >= a; i--)
#define bfff(i,a,b) for (int i = b; i >= a; i--)

using namespace std;
long double typedef ld;
unsigned int typedef ui;
long long int typedef li;
pair<int,int> typedef pii;
pair<li,li> typedef pli;
pair<ld,ld> typedef pld;
vector<vector<int>> typedef graph;
unsigned long long int typedef ull;
//const int mod = 998244353;
//const int mod = 1000000007;







//Note to self: Check for overflow

int power(int a, int n, int mod)
{
    li c=1;
    while (n)
    {
        if (n&1) (c*=a)%mod;
        a=(li)a*a%mod,n>>=1;
    }
    return c;
}

struct hesiranje
{
    int p,mod;
    int w[26];

    void setprost(int _)
    {
        p=_;
    }
    void setmod(int _)
    {
        mod=_;
    }

    int ps[10004],pi[10004];

    int pre[10004],suf[10004];

    void build(string s, int n)
    {
        mt19937 rng(time(NULL));
        ff(i,0,26) w[i]=rng()%mod;

        ps[0]=1,pi[0]=1;
        fff(i,1,n) ps[i]=(li)ps[i-1]*p%mod;
        fff(i,1,n) pi[i]=power(ps[i],mod-2,mod);

        fff(i,1,n) pre[i]=((li)pre[i-1]*p+w[s[i-1]-'a'])%mod;
        bfff(i,1,n) suf[i]=((li)suf[i+1]*p+w[s[i-1]-'a'])%mod;
    }

    int Hash(int l, int r)
    {
        return (pre[r]+mod-(li)pre[l-1]*ps[r-l+1]%mod)%mod;
    }

    int rHash(int l, int r)
    {
        return (suf[l]+mod-(li)suf[r+1]*ps[r-l+1]%mod)%mod;
    }
} h1,h2;

int main()
{
    FAST;

    string s; cin>>s;
    int n=(int)s.size();

    h1.setprost(1000003),h1.setmod(998244353);
    h2.setprost(998244353),h2.setmod(1000000007);
    h1.build(s,n),h2.build(s,n);

    li ans=0;
    fff(k,1,n)
    {
        unordered_map<li,int> kolko;
        fff(i,k,n) if (h1.Hash(i-k+1,i)==h1.rHash(i-k+1,i) && h2.Hash(i-k+1,i)==h2.rHash(i-k+1,i))
        {
            li sta=(li)h1.Hash(i-k+1,i)*(1ll<<30) + h2.Hash(i-k+1,i);
            kolko[sta]++;
        }

        for (auto it : kolko) ans=max(ans,(li)it.yy*k);
    }
    cout<<ans<<"\n";
}

//Note to self: Check for overflow

Compilation message

palindrome.cpp: In function 'int power(int, int, int)':
palindrome.cpp:42:24: warning: value computed is not used [-Wunused-value]
   42 |         if (n&1) (c*=a)%mod;
      |                  ~~~~~~^~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 328 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 328 KB Output is correct
14 Correct 1 ms 328 KB Output is correct
15 Correct 0 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 324 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 324 KB Output is correct
23 Correct 1 ms 296 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 324 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 340 KB Output is correct
2 Correct 22 ms 328 KB Output is correct
3 Correct 40 ms 368 KB Output is correct
4 Correct 17 ms 340 KB Output is correct
5 Correct 39 ms 372 KB Output is correct
6 Correct 39 ms 340 KB Output is correct
7 Correct 16 ms 396 KB Output is correct
8 Correct 29 ms 340 KB Output is correct
9 Correct 16 ms 388 KB Output is correct
10 Correct 15 ms 392 KB Output is correct
11 Correct 15 ms 340 KB Output is correct
12 Correct 18 ms 340 KB Output is correct

Subtask #3
0 / 24.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1078 ms 596 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 26.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 1236 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Runtime error 3 ms 2524 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -