oj.uz

Submission #1106432

# Submission time Handle Problem Language Result Execution time Memory
1106432 2024-10-30T10:31:56 Z cot7302 Necklace (Subtask 1-3) (BOI19_necklace1) C++17
29 / 85
 1500 ms 88392 KB 
#pragma GCC optimize("O3,inline")
#include <bits/stdc++.h>
#define ALL(X) begin(X), end(X)
using namespace std;
using i64 = long long;
 
template <class T>
using vec = vector<T>;
 
template <class T>
istream& operator>>(istream& is, vec<T>& V) {
    for (auto& x : V) is >> x;
    return is;
}
 
mt19937_64 rng((uint64_t)time(0));
 
constexpr int kN = 3'000;
 
using Hs = uint64_t;
 
Hs hs[2][kN + 2], pw[kN + 1];
 
void solve() {
    auto st = clock();
    string S, T; cin >> S >> T;
    int n = size(S);
    int m = size(T);
    bool fl = false;
    if (n < m)
        swap(n, m), swap(S, T), fl = true;
    Hs bs{};
    for (auto x = rng(); (bs = x, x) % 2 == 0; )
        x = rng();
    pw[0] = 1;
    for (int i = 0; i < m; i++) {
        pw[i + 1] = pw[i] * bs;
        hs[0][i + 1] = hs[0][i] * bs + T[i];
    }
    for (int i = m - 1; i >= 0; i--) {
        hs[1][i] = hs[1][i + 1] * bs + T[i];
    }
    auto get_0 = [&](int l, int r) -> Hs {
        return hs[0][r] - hs[0][l] * pw[r - l];
    };
    auto get_1 = [&](int l, int r) -> Hs {
        return hs[1][l] - hs[1][r] * pw[r - l];
    };
    map<Hs, int> mp;
    for (int i = 0; i < n; i++) {
        Hs h{};
        for (int j = i; j < n; j++) {
            h = h * bs + S[j];
            mp[h] = i;
        }
    }
    vec<int> id(m);
    iota(ALL(id), 0);
    shuffle(ALL(id), rng);
    int len{};
    pair<int, int> ans{};
    for (int t = 0; t < m; t++) {
        if (clock() - st >= 1.47 * CLOCKS_PER_SEC)
            break;
        for (int i = m - 1; i >= id[t]; i--) {
            if (i - id[t] + 1 <= len) break;
            Hs h = get_0(id[t], i + 1);
            Hs r = get_1(id[t], i + 1);
            bool f = false;
            Hs p = pw[i - id[t]];
            for (int j = id[t]; j <= i; j++) {
                if (i - id[t] + 1 > len) {
                    auto it = mp.find(h);
                    if (it != end(mp)) {
                        len = i - id[t] + 1, ans = {it->second, id[t]};
                        f = true;
                        break;
                    }
                }
                h -= p * T[j];
                h *= bs;
                h += T[j];
            }
            if (f) break;
            for (int j = i; j >= id[t]; j--) {
                if (i - id[t] + 1 > len) {
                    auto it = mp.find(r);
                    if (it != end(mp)) {
                        len = i - id[t] + 1, ans = {it->second, id[t]};
                        f = true;
                        break;
                    }
                }
                r -= p * T[j];
                r *= bs;
                r += T[j];
            }
            if (f) break;
        }
    }
    if (fl)
        swap(ans.first, ans.second);
    cout << len << '\n';
    cout << ans.first << ' ' << ans.second << '\n';
}
 
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    solve();
}

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 592 KB Output is correct
2 Correct 3 ms 336 KB Output is correct
3 Correct 8 ms 724 KB Output is correct
4 Correct 11 ms 592 KB Output is correct
5 Correct 25 ms 592 KB Output is correct

Subtask #2
4.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 592 KB Output is correct
2 Correct 3 ms 336 KB Output is correct
3 Correct 8 ms 724 KB Output is correct
4 Correct 11 ms 592 KB Output is correct
5 Correct 25 ms 592 KB Output is correct
6 Correct 197 ms 1104 KB Output is correct
7 Correct 498 ms 2128 KB Output is correct
8 Correct 1478 ms 4700 KB Output is correct
9 Correct 1473 ms 4820 KB Output is correct
10 Correct 1484 ms 5316 KB Output is correct
11 Partially correct 1479 ms 5292 KB Output is partially correct
12 Partially correct 1474 ms 4176 KB Output is partially correct

Subtask #3
0.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 592 KB Output is correct
2 Correct 3 ms 336 KB Output is correct
3 Correct 8 ms 724 KB Output is correct
4 Correct 11 ms 592 KB Output is correct
5 Correct 25 ms 592 KB Output is correct
6 Correct 197 ms 1104 KB Output is correct
7 Correct 498 ms 2128 KB Output is correct
8 Correct 1478 ms 4700 KB Output is correct
9 Correct 1473 ms 4820 KB Output is correct
10 Correct 1484 ms 5316 KB Output is correct
11 Partially correct 1479 ms 5292 KB Output is partially correct
12 Partially correct 1474 ms 4176 KB Output is partially correct
13 Execution timed out 1569 ms 88392 KB Time limit exceeded
14 Halted 0 ms 0 KB -