oj.uz

Submission #602024

# Submission time Handle Problem Language Result Execution time Memory
602024 2022-07-22T13:52:00 Z ace5 Palindromes (APIO14_palindrome) C++17
73 / 100
 320 ms 131072 KB 
#include <bits/stdc++.h>
#include <random>
#include <ext/rope>
#include <complex>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;

const int alf = 26;
const int maxn = 300005;

struct sf
{
    sf(){len = 0;link = 0;l = 0;c = 0;};
    int64_t go[alf];
    int64_t len,link;
    int64_t l;
    int64_t c;
};


vector<sf> sa(maxn);

void init()
{
    sa[0].link = -1;
    sa[0].len = 0;
    sa[0].c = 0;
    sa[0].l = -1;
    for(int i = 0;i < sa.size();++i)
    {
        for(int j = 0;j < alf;++j)
            sa[i].go[j] = -1;
    }
    return ;

}

int last = 0,sz = 1;


void add(char c)
{
    int x = c-'a';
    int cur = sz++;
    sa[cur].len = sa[last].len+1;
    sa[cur].l = 0;
    sa[cur].c = 1;
    int p = last;
    while(p != -1 && sa[p].go[x] == -1)
    {
        sa[p].go[x] = cur;
        p = sa[p].link;
    }
   // cout << p << ' ';
    if(p == -1)
    {
        sa[cur].link = 0;
    }
    else
    {
        int q = sa[p].go[x];
        if(sa[p].len == sa[q].len-1)
        {
            sa[cur].link = q;
        }
        else
        {
            int clone = sz++;
            sa[clone].len = sa[p].len + 1;
            sa[clone].link = sa[q].link;
            for(int i = 0;i < alf;++i)
                sa[clone].go[i] = sa[q].go[i];
            sa[clone].c = 0;
            sa[clone].l = sa[q].l + sa[q].len - sa[p].len - 1;
            sa[q].link = sa[cur].link = clone;
            int cp = p;
            while(sa[cp].go[x] == q)
            {
                sa[cp].go[x] = clone;
                cp = sa[cp].link;
            }
        }
    }
    last = cur;
    return ;
}
vector<int64_t> phash(maxn),shash(maxn),st(maxn);
const int64_t mod = int64_t(1e9)+7,p = 101;

bool qp(int64_t l,int64_t r)
{
   // cout << shash[l] << ' ' << ((shash[r+1]*(st[r-l+1]))%mod) << "\n";
    if((phash[r+1]-((phash[l]*(st[r-l+1]))%mod)+mod)%mod == (shash[l]-((shash[r+1]*(st[r-l+1]))%mod)+mod)%mod)
        return true;
    else
        return false;
}

struct ev
{
    ev(){t =0;c = 0;oc = 0;l = 0;};
    ev(int64_t  _t,bool _c,int64_t _oc,int64_t _l){t =_t;c = _c;oc = _oc;l = _l;};
    int64_t t;
    bool c;
    int64_t oc;
    int64_t l;
    bool operator <(const ev& other)const
    {
        if(t != other.t)
            return t < other.t;
        if(c == other.c)
            return oc < other.oc;
        else
        {
            if(c == 0)
            {
                if(oc == 0)
                    return 1;
                else
                    return 0;
            }
            else
            {
                if(other.oc == 0)
                    return 0;
                else
                    return 1;
            }
        }
    }
};




int main()
{
    st[0] = 1;
    for(int i =1;i < maxn;++i)
    {
        st[i] = (p*st[i-1])%mod;
    }
    string s;
    cin >> s;
    int n = s.size();
    init();
    for(int i = 0;i < s.size();++i)
    {
       // cout << 1;
        add(s[i]);
    }
    vector<pair<int,int>> tr;
    for(int i = 1;i < sz;++i)
    {
        tr.push_back({sa[i].len,i});
    }
    sort(tr.rbegin(),tr.rend());
    for(int i = 0;i < sz-1;++i)
    {
        sa[sa[tr[i].second].link].c += sa[tr[i].second].c;
    }
   // cout << 1;
    int64_t thash = 0;
    phash[0] = thash;
    for(int i = 0;i < s.size();++i)
    {
        thash *= p;
        thash += s[i];
        thash = thash%mod;
        phash[i+1] = thash;
    }
    thash = 0;
    shash[n] = thash;
    for(int i = int(s.size())-1;i >= 0;--i)
    {
        thash *= p;
        thash += s[i];
        thash = thash%mod;
        shash[i] = thash;
    }
    vector<ev> lg;

    for(int i = 1;i < sz;++i)
    {
       // cout << sa[i].link << ' ' << sa[i].l << ' ' << sa[i].len << ' ' << sa[i].c << "\n";
        lg.push_back(ev(sa[i].l + sa[i].len - 1,1,sa[i].c,sa[i].l));
    }
    for(int i = 0;i < n;++i)
    {
        int l = max(0,i-(n-i)+1),r = i;
        while(l < r)
        {
            int m = (l+r)/2;
            if(qp(m,2*i-m))
                r = m;
            else
                l = m+1;
        }
        //cout << l << ' ' << i << "\n";
        lg.push_back(ev(i,0,0,2*i));
        lg.push_back(ev(2*i-l,0,1,2*i));
    }
    for(int i = 1;i < n;++i)
    {
        int l = max(1,i-(n-i)+1),r = i+1;
        while(l < r)
        {
            int m = (l+r)/2;
            if(qp(m-1,2*i-m))
                r = m;
            else
                l = m+1;
        }
        //cout << l << ' ' << i << "\n";
        if(l <= i)
        {
            lg.push_back(ev(i,0,0,2*i-1));
            lg.push_back(ev(2*i-l,0,1,2*i-1));

        }
    }
    sort(lg.begin(),lg.end());
    int64_t ans = 0;
    set<int> ss;
    for(int i = 0;i < lg.size();++i)
    {
        ev x = lg[i];
        if(x.c == 0)
        {
            if(x.oc == 0)
            {
                ss.insert(x.l);
            }
            else
                ss.erase(x.l);
        }
        else
        {
            auto it = ss.lower_bound((x.l+x.t));
            int64_t xx = (*it);
         //   cout << xx << ' ' << x.l << ' ' << x.t << "\n";
            if(xx%2 == 0)
                ans = max(ans,((x.t-(xx/2))*2+1)*(x.oc));
            else
                ans = max(ans,((x.t-(xx/2))*2)*(x.oc));
        }
    }
    cout << ans;
    return 0;
}

Compilation message

palindrome.cpp: In function 'void init()':
palindrome.cpp:33:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<sf>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for(int i = 0;i < sa.size();++i)
      |                   ~~^~~~~~~~~~~
palindrome.cpp: In function 'int main()':
palindrome.cpp:151:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  151 |     for(int i = 0;i < s.size();++i)
      |                   ~~^~~~~~~~~~
palindrome.cpp:169:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  169 |     for(int i = 0;i < s.size();++i)
      |                   ~~^~~~~~~~~~
palindrome.cpp:229:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<ev>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  229 |     for(int i = 0;i < lg.size();++i)
      |                   ~~^~~~~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 40 ms 77744 KB Output is correct
2 Correct 37 ms 77780 KB Output is correct
3 Correct 36 ms 77780 KB Output is correct
4 Correct 42 ms 77768 KB Output is correct
5 Correct 39 ms 77804 KB Output is correct
6 Correct 37 ms 77780 KB Output is correct
7 Correct 37 ms 77776 KB Output is correct
8 Correct 38 ms 77760 KB Output is correct
9 Correct 37 ms 77708 KB Output is correct
10 Correct 40 ms 77692 KB Output is correct
11 Correct 37 ms 77780 KB Output is correct
12 Correct 38 ms 77756 KB Output is correct
13 Correct 37 ms 77716 KB Output is correct
14 Correct 39 ms 77812 KB Output is correct
15 Correct 38 ms 77808 KB Output is correct
16 Correct 40 ms 77788 KB Output is correct
17 Correct 37 ms 77780 KB Output is correct
18 Correct 37 ms 77692 KB Output is correct
19 Correct 37 ms 77796 KB Output is correct
20 Correct 37 ms 77796 KB Output is correct
21 Correct 36 ms 77756 KB Output is correct
22 Correct 38 ms 77792 KB Output is correct
23 Correct 37 ms 77792 KB Output is correct
24 Correct 37 ms 77780 KB Output is correct
25 Correct 37 ms 77780 KB Output is correct
26 Correct 36 ms 77796 KB Output is correct
27 Correct 37 ms 77780 KB Output is correct
28 Correct 42 ms 77792 KB Output is correct
29 Correct 38 ms 77816 KB Output is correct
30 Correct 40 ms 77792 KB Output is correct
31 Correct 38 ms 77772 KB Output is correct
32 Correct 39 ms 77800 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 40 ms 77984 KB Output is correct
2 Correct 39 ms 77996 KB Output is correct
3 Correct 40 ms 78156 KB Output is correct
4 Correct 39 ms 78040 KB Output is correct
5 Correct 38 ms 78192 KB Output is correct
6 Correct 42 ms 78180 KB Output is correct
7 Correct 39 ms 77928 KB Output is correct
8 Correct 41 ms 77920 KB Output is correct
9 Correct 39 ms 78088 KB Output is correct
10 Correct 40 ms 78012 KB Output is correct
11 Correct 38 ms 77920 KB Output is correct
12 Correct 38 ms 78176 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 44 ms 79044 KB Output is correct
2 Correct 47 ms 80112 KB Output is correct
3 Correct 50 ms 80028 KB Output is correct
4 Correct 49 ms 80072 KB Output is correct
5 Correct 42 ms 79044 KB Output is correct
6 Correct 45 ms 80024 KB Output is correct
7 Correct 50 ms 80128 KB Output is correct
8 Correct 45 ms 80000 KB Output is correct
9 Correct 46 ms 80084 KB Output is correct
10 Correct 47 ms 80016 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 124 ms 95340 KB Output is correct
2 Correct 129 ms 95720 KB Output is correct
3 Correct 158 ms 99096 KB Output is correct
4 Correct 178 ms 112168 KB Output is correct
5 Correct 108 ms 95396 KB Output is correct
6 Correct 128 ms 95680 KB Output is correct
7 Correct 158 ms 95988 KB Output is correct
8 Correct 124 ms 95628 KB Output is correct
9 Correct 136 ms 95732 KB Output is correct
10 Correct 131 ms 95748 KB Output is correct

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 320 ms 115620 KB Output is correct
2 Runtime error 133 ms 131072 KB Execution killed with signal 11
3 Halted 0 ms 0 KB -