Submission #1259117

#	Time	Username	Problem	Language	Result	Execution time	Memory
1259117		newsboy	Necklace (Subtask 4) (BOI19_necklace4)	C++20	0 / 15	173 ms	53360 KiB

necklace

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <set>
#include <map>
#include <numeric>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <climits>
#include <queue>
#include <deque>
#include <stack>
#include <cmath>
#include <tuple>
#include <cassert>
#include <array>
#include <list>
#include <random>
#include <initializer_list>
#include <chrono>
using namespace std;
using i64 = long long;
using u64 = unsigned long long;

vector<int> prefixFunction(string& s) {
    vector<int> pi(s.size());
    for (int i = 1; i < s.size(); i++) {
        int j = pi[i - 1];
        while (j > 0 && s[i] != s[j]) {
            j = pi[j - 1];
        }
        if (s[i] == s[j]) {
            j++;
        }
        pi[i] = j;
    }
    return pi;
}

string s, t;

void work(int& res, int& ls, int& lt, bool& o) {
    if (o) {
        reverse(s.begin(), s.end());
    }
    int n = s.size();
    int m = t.size();
    string g = s + "?" + t;
    vector<vector<int>> pi(n);
    for (int i = 0; i < n; i++) {
        pi[i] = prefixFunction(g);
        g.erase(g.begin());
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            int x = pi[i][n - i + 1 + j];
            if (x > res) {
                res = x;
                ls = i;
                lt = j - x + 1;
            }
            if (i + x < n && n - (i + x) + 1 + (j - x) < pi[i].size()) {
                int y = pi[i + x][n - (i + x) + 1 + (j - x)];
                if (x + y > res) {
                    res = x + y;
                    ls = (o ? n - (i + res - 1) - 1 : i);
                    lt = (j - x) - y + 1;
                }
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> s >> t;
    bool o = 0;
    int res = 0;
    int ls = -1, lt = -1;
    work(res, ls, lt, o);
    o ^= 1;
    work(res, ls, lt, o);
    cout << res << '\n';
    cout << ls << " " << lt << '\n';
}

• Subtask 1: 0 / 15