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답안 #1081674

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1081674 2024-08-30T09:02:43 Z Joshua_Andersson Necklace (Subtask 1-3) (BOI19_necklace1) C++14
9 / 85
 102 ms 71072 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define int ll
const int inf = int(1e18);

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> p2;

#define rep(i, high) for (int i = 0; i < high; i++)
#define repp(i, low, high) for (int i = low; i < high; i++)
#define repe(i, container) for (auto& i : container)
#define sz(container) ((int)container.size())
#define all(x) begin(x),end(x)

inline void fast() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); }

#if _LOCAL
#define assert(x) if (!(x)) __debugbreak()
#endif

typedef unsigned long long ull;

struct RollingHash
{
    vector<ull> suf, b;
    int mod;
    RollingHash(string& s, ull base = 131, ull mod = 1e9 + 7) : mod(mod), suf(s.size() + 1), b(s.size() + 1)
    {
        b[0] = 1;
        b[1] = base;

        for (int i = sz(s) - 1; i >= 0; i--)
        {
            suf[i] = (suf[i + 1] * base + s[i]) % mod;
        }

        repp(i, 2, s.size() + 1)
        {
            b[i] = b[i - 1] * b[1] % mod;
        }
    }

    ull gethash(int l, int r) // hash s[l, r]
    {
        ull rv = (suf[r + 1] * b[r - l + 1]) % mod;
        return suf[l] + mod * (suf[l] < rv) - rv;
    }
};

struct DoubleHash
{
    RollingHash h1;
    RollingHash h2;
    DoubleHash(string& s, ull mod = 1e9 + 7) : h1(s, 157, mod), h2(s, 131, mod) {}
    ull gethash(int l, int r)
    {
        return (h1.gethash(l, r) << 32) + h2.gethash(l, r);
    }
};

pair<int,p2> best(string a, string b, bool rev)
{
    int ret = -1;
    p2 r = p2(-1, -1);
    vvi lcp(sz(a), vi(sz(b)));
    DoubleHash h1(a);
    DoubleHash h2(b);
    mt19937 rng;
    uniform_int_distribution<int> da(0, sz(a) - 1);
    uniform_int_distribution<int> db(0, sz(b) - 1);
    int l = 10;

    rep(i, 1000)
    {
        int starta = da(rng);
        int startb = db(rng);
        p2 c = { starta,startb };

        while (starta+1 < sz(a) && startb+1 < sz(b) && a[starta] == b[startb])
        {
            starta++;
            startb++;
        }

        int sa = starta;
        tie(starta, startb) = c;

        while (starta > 0 && startb > 0 && a[starta] == b[startb])
        {
            starta--;
            startb--;
        }
        starta = sa;

        int rp = 0;
        repp(rlen, 1, l * 2 + 1)
        {
            int i = starta - rlen;
            int j = startb;
            if (i < 0 || j + rlen - 1 >= sz(b)) break;
            bool good = h1.gethash(i, i + rlen - 1) == h2.gethash(j, j + rlen - 1);
            if (good) rp = rlen;
        }
        int lp = 0;
        repp(llen, 1, l * 2+ 1)
        {
            int i = starta;
            int j = startb - llen;
            if (j < 0 || i + llen - 1 >= sz(a)) break;
            bool good = h1.gethash(i, i + llen - 1) == h2.gethash(j, j + llen - 1);
            if (good) lp = llen;
        }

        if (rp + lp > ret)
        {
            //assert(rp + lp != 84);
            r = { starta - rp,startb - lp };
            if (rev) r.second = sz(b) - r.second - rp - lp;
            ret = rp + lp;
            l = max(l, ret);
        }
        
    }
    
    return { ret, r };
}

signed main()
{
    fast();

    string a, b;
    cin >> a >> b;
    pair<int, p2> ans = { -1000,p2(0,0) };
    ans = max(ans, best(a, b, 0));
    reverse(all(b));
    ans = max(ans, best(a, b, 1));
    cout << ans.first << "\n" << ans.second.first << " " << ans.second.second;

    return 0;
}

Compilation message

necklace.cpp: In constructor 'RollingHash::RollingHash(std::string&, ull, ull)':
necklace.cpp:29:9: warning: 'RollingHash::mod' will be initialized after [-Wreorder]
   29 |     int mod;
      |         ^~~
necklace.cpp:28:17: warning:   'std::vector<long long unsigned int> RollingHash::suf' [-Wreorder]
   28 |     vector<ull> suf, b;
      |                 ^~~
necklace.cpp:30:5: warning:   when initialized here [-Wreorder]
   30 |     RollingHash(string& s, ull base = 131, ull mod = 1e9 + 7) : mod(mod), suf(s.size() + 1), b(s.size() + 1)
      |     ^~~~~~~~~~~
necklace.cpp:13:48: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 | #define repp(i, low, high) for (int i = low; i < high; i++)
......
   40 |         repp(i, 2, s.size() + 1)
      |              ~~~~~~~~~~~~~~~~~~                 
necklace.cpp:40:9: note: in expansion of macro 'repp'
   40 |         repp(i, 2, s.size() + 1)
      |         ^~~~

Subtask #1
5.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 344 KB Output is correct
2 Partially correct 2 ms 348 KB Output is partially correct
3 Partially correct 1 ms 348 KB Output is partially correct
4 Partially correct 1 ms 348 KB Output is partially correct
5 Partially correct 1 ms 348 KB Output is partially correct

Subtask #2
4.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 344 KB Output is correct
2 Partially correct 2 ms 348 KB Output is partially correct
3 Partially correct 1 ms 348 KB Output is partially correct
4 Partially correct 1 ms 348 KB Output is partially correct
5 Partially correct 1 ms 348 KB Output is partially correct
6 Partially correct 8 ms 1744 KB Output is partially correct
7 Partially correct 7 ms 1628 KB Output is partially correct
8 Partially correct 5 ms 1448 KB Output is partially correct
9 Partially correct 5 ms 1628 KB Output is partially correct
10 Partially correct 2 ms 1628 KB Output is partially correct
11 Partially correct 2 ms 1628 KB Output is partially correct
12 Partially correct 5 ms 1628 KB Output is partially correct

Subtask #3
0.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 344 KB Output is correct
2 Partially correct 2 ms 348 KB Output is partially correct
3 Partially correct 1 ms 348 KB Output is partially correct
4 Partially correct 1 ms 348 KB Output is partially correct
5 Partially correct 1 ms 348 KB Output is partially correct
6 Partially correct 8 ms 1744 KB Output is partially correct
7 Partially correct 7 ms 1628 KB Output is partially correct
8 Partially correct 5 ms 1448 KB Output is partially correct
9 Partially correct 5 ms 1628 KB Output is partially correct
10 Partially correct 2 ms 1628 KB Output is partially correct
11 Partially correct 2 ms 1628 KB Output is partially correct
12 Partially correct 5 ms 1628 KB Output is partially correct
13 Partially correct 102 ms 71072 KB Output is partially correct
14 Partially correct 100 ms 71004 KB Output is partially correct
15 Partially correct 75 ms 67108 KB Output is partially correct
16 Partially correct 69 ms 70112 KB Output is partially correct
17 Incorrect 63 ms 68800 KB Output isn't correct
18 Halted 0 ms 0 KB -