oj.uz

Submission #565616

# Submission time Handle Problem Language Result Execution time Memory
565616 2022-05-21T07:32:58 Z Forested Palindromes (APIO14_palindrome) C++17
100 / 100
 68 ms 64184 KB 
// ===== template.hpp =====
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

#define OVERRIDE(a, b, c, d, ...) d
#define REP2(i, n) for (i32 i = 0; i < (i32) (n); ++i)
#define REP3(i, m, n) for (i32 i = (i32) (m); i < (i32) (n); ++i)
#define REP(...) OVERRIDE(__VA_ARGS__, REP3, REP2)(__VA_ARGS__)
#define PER(i, n) for (i32 i = (i32) (n) - 1; i >= 0; --i)
#define ALL(x) begin(x), end(x)

using namespace std;

using u32 = unsigned int;
using u64 = unsigned long long;
using u128 = __uint128_t;
using i32 = signed int;
using i64 = signed long long;
using i128 = __int128_t;
using f64 = double;
using f80 = long double;

template <typename T>
using Vec = vector<T>;

template <typename T>
bool chmin(T &x, const T &y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}
template <typename T>
bool chmax(T &x, const T &y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}

istream &operator>>(istream &is, i128 &x) {
    i64 v;
    is >> v;
    x = v;
    return is;
}
ostream &operator<<(ostream &os, i128 x) {
    os << (i64) x;
    return os;
}
istream &operator>>(istream &is, u128 &x) {
    u64 v;
    is >> v;
    x = v;
    return is;
}
ostream &operator<<(ostream &os, u128 x) {
    os << (u64) x;
    return os;
}

template <typename F, typename Comp = less<>>
Vec<i32> sort_index(i32 n, F f, Comp comp = Comp()) {
    Vec<i32> idx(n);
    iota(ALL(idx), 0);
    sort(ALL(idx), [&](i32 i, i32 j) -> bool {
        return comp(f(i), f(j));
    });
    return idx;
}

[[maybe_unused]] constexpr i32 INF = 1000000100;
[[maybe_unused]] constexpr i64 INF64 = 3000000000000000100;

struct FastIO {
    FastIO() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        cout << fixed << setprecision(10);
    }
} fast_io;
// ===== template.hpp =====

#ifdef DEBUGF
#include "cpl/template/debug.hpp"
#else
#define DBG(x) (void) 0
#endif

// ===== eertree.hpp =====

#include <vector>
#include <array>
#include <algorithm>
#include <utility>
#include <cassert>

template <int SIGMA = 26>
class Eertree {
    std::vector<int> seq;
    std::vector<std::pair<int, int>> range;
    std::vector<int> suf_link;
    std::vector<std::array<int, SIGMA>> ext;
    std::vector<int> freq;
    int longest_suffix;
    
public:
    Eertree() : seq(), range(2), suf_link(2), ext(2), freq(2), longest_suffix(1) {
        range[0] = std::pair<int, int>(0, -1);
        suf_link[0] = -1;
        std::fill(ext[0].begin(), ext[0].end(), -1);
        freq[0] = 0;
        range[1] = std::pair<int, int>(0, 0);
        suf_link[1] = 0;
        std::fill(ext[1].begin(), ext[1].end(), -1);
        freq[1] = 0;
    }
    
    void reserve(int n) {
        seq.reserve(n);
    }
    
    // amortized O(SIGMA)
    bool push(int c) {
        assert(c < SIGMA);
        seq.push_back(c);
        int cur = longest_suffix;
        while (true) {
            bool is_palindrome = false;
            {
                int len = range[cur].second - range[cur].first;
                is_palindrome = ((int) seq.size() >= len + 2 && seq[(int) seq.size() - len - 2] == c);
            }
            if (is_palindrome) {
                if (ext[cur][c] != -1) {
                    ++freq[ext[cur][c]];
                    longest_suffix = ext[cur][c];
                    return false;
                }
                break;
            }
            cur = suf_link[cur];
        }
        int this_node = (int) range.size();
        ext[cur][c] = this_node;
        {
            int len = range[cur].second - range[cur].first + 2;
            range.emplace_back((int) seq.size() - len, (int) seq.size());
        }
        ext.emplace_back(std::array<int, SIGMA>());
        std::fill(ext.back().begin(), ext.back().end(), -1);
        freq.push_back(1);
        longest_suffix = this_node;
        if (range[this_node].second - range[this_node].first == 1) {
            suf_link.push_back(1);
            return true;
        }
        cur = suf_link[cur];
        while (true) {
            bool is_palindrome = false;
            {
                int len = range[cur].second - range[cur].first;
                is_palindrome = ((int) seq.size() >= len + 2 && seq[(int) seq.size() - len - 2] == c);
            }
            if (is_palindrome && ext[cur][c] != -1) {
                suf_link.push_back(ext[cur][c]);
                return true;
            }
            cur = suf_link[cur];
        }
        assert(false);
    }
    
    int num_palindromes() const {
        return (int) range.size() - 2;
    }
    
    const std::pair<int, int> &operator[](int i) const {
        return range[i + 2];
    }
    
    std::vector<std::pair<int, int>> palindromes() const {
        return std::vector<std::pair<int, int>>(range.begin() + 2, range.end());
    }
    
    // O(|S|)
    std::vector<int> frequencies() const {
        std::vector<int> ret(freq.size() - 2, 0);
        for (int i = (int) freq.size() - 1; i >= 2; --i) {
            ret[i - 2] += freq[i];
            if (suf_link[i] >= 2) {
                ret[suf_link[i] - 2] += ret[i - 2];
            }
        }
        return ret;
    }
};
// ===== eertree.hpp =====

int main() {
    string s;
    cin >> s;
    Eertree<> eertree;
    for (char c : s) {
        eertree.push(c - 'a');
    }
    Vec<i32> freq = eertree.frequencies();
    i64 ans = 0;
    REP(i, freq.size()) {
        auto [l, r] = eertree[i];
        chmax(ans, (i64) freq[i] * (r - l));
        //cout << s.substr(l, r - l) << ' ' << freq[i] << '\n';
    }
    cout << ans << '\n';
}

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 1 ms 316 KB Output is correct
19 Correct 1 ms 340 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 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 316 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 316 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 320 KB Output is correct
31 Correct 1 ms 212 KB Output is correct
32 Correct 1 ms 340 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 468 KB Output is correct
6 Correct 1 ms 496 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 468 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2240 KB Output is correct
2 Correct 2 ms 2240 KB Output is correct
3 Correct 2 ms 2240 KB Output is correct
4 Correct 2 ms 2240 KB Output is correct
5 Correct 2 ms 2240 KB Output is correct
6 Correct 2 ms 2240 KB Output is correct
7 Correct 2 ms 2240 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 1260 KB Output is correct

Subtask #4
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 15824 KB Output is correct
2 Correct 14 ms 15880 KB Output is correct
3 Correct 16 ms 15772 KB Output is correct
4 Correct 15 ms 15860 KB Output is correct
5 Correct 16 ms 15860 KB Output is correct
6 Correct 13 ms 16116 KB Output is correct
7 Correct 15 ms 16116 KB Output is correct
8 Correct 3 ms 1104 KB Output is correct
9 Correct 6 ms 4580 KB Output is correct
10 Correct 14 ms 16488 KB Output is correct

Subtask #5
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 52 ms 63160 KB Output is correct
2 Correct 51 ms 64184 KB Output is correct
3 Correct 53 ms 63468 KB Output is correct
4 Correct 68 ms 63528 KB Output is correct
5 Correct 55 ms 63536 KB Output is correct
6 Correct 50 ms 64184 KB Output is correct
7 Correct 35 ms 33796 KB Output is correct
8 Correct 8 ms 3408 KB Output is correct
9 Correct 9 ms 3524 KB Output is correct
10 Correct 37 ms 33364 KB Output is correct
11 Correct 60 ms 63536 KB Output is correct
12 Correct 11 ms 7116 KB Output is correct