Submission #133050

#	Time	Username	Problem	Language	Result	Execution time	Memory
133050		E869120	Necklace (Subtask 1-3) (BOI19_necklace1)	C++14	25 / 85	1580 ms	332804 KiB

necklace

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;

const long long mod = 2147483647LL;

string S, T;
vector<pair<long long, int>> vec[3009];

long long hash_val(string U) {
	long long r = 0;
	for (int i = 0; i < U.size(); i++) {
		r *= 100LL;
		r += (long long)(U[i] - 'a' + 1LL);
		r %= mod;
	}
	return r;
}

vector<long long> get_substring(string U) {
	if (U == "abcd") {
		U += "";
	}
	vector<long long> a, b, c;
	a.push_back(0);
	for (int i = 0; i < U.size(); i++) {
		a.push_back((100LL * a[a.size() - 1] + (long long)(U[i] - 'a' + 1)) % mod);
	}
	b.push_back(0); long long r = 1;
	for (int i = U.size() - 1; i >= 0; i--) {
		b.push_back((b[b.size() - 1] + r * (long long)(U[i] - 'a' + 1)) % mod);
		r *= 100LL; r %= mod;
	}
	reverse(b.begin(), b.end());

	r = 1;
	for (int i = 0; i < U.size(); i++) {
		long long s = a[i] + r * b[i];
		s %= mod;
		c.push_back(s);
		r *= 100LL; r %= mod;
	}
	return c;
}

int main() {
	cin >> S >> T;
	for (int i = 0; i < S.size(); i++) {
		for (int j = i + 1; j <= S.size(); j++) {
			string G = S.substr(i, j - i);
			vector<long long> V1 = get_substring(G); reverse(G.begin(), G.end());
			vector<long long> V2 = get_substring(G);
			for (int k = 0; k < V1.size(); k++) vec[j - i].push_back(make_pair(V1[k], i));
			for (int k = 0; k < V2.size(); k++) vec[j - i].push_back(make_pair(V2[k], i));
		}
	}
	for (int i = 0; i <= S.size(); i++) sort(vec[i].begin(), vec[i].end());

	int maxn = 0; pair<int, int> maxid = make_pair(-1, -1);
	for (int i = 0; i < T.size(); i++) {
		for (int j = i + 1; j <= T.size(); j++) {
			string G = T.substr(i, j - i);
			long long v = hash_val(G);
			
			int pos1 = lower_bound(vec[j - i].begin(), vec[j - i].end(), make_pair(v, 0)) - vec[j - i].begin();
			if (pos1 < vec[j - i].size() && vec[j - i][pos1].first == v) {
				if (maxn < j - i) {
					maxn = j - i;
					maxid = make_pair(vec[j - i][pos1].second, i);
				}
			}
		}
	}
	cout << maxn << endl;
	cout << maxid.first << " " << maxid.second << endl;
	return 0;
}

Compilation message (stderr)

necklace.cpp: In function 'long long int hash_val(std::__cxx11::string)':
necklace.cpp:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < U.size(); i++) {
                  ~~^~~~~~~~~~
necklace.cpp: In function 'std::vector<long long int> get_substring(std::__cxx11::string)':
necklace.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < U.size(); i++) {
                  ~~^~~~~~~~~~
necklace.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < U.size(); i++) {
                  ~~^~~~~~~~~~
necklace.cpp: In function 'int main()':
necklace.cpp:50:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < S.size(); i++) {
                  ~~^~~~~~~~~~
necklace.cpp:51:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = i + 1; j <= S.size(); j++) {
                       ~~^~~~~~~~~~~
necklace.cpp:55:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int k = 0; k < V1.size(); k++) vec[j - i].push_back(make_pair(V1[k], i));
                    ~~^~~~~~~~~~~
necklace.cpp:56:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int k = 0; k < V2.size(); k++) vec[j - i].push_back(make_pair(V2[k], i));
                    ~~^~~~~~~~~~~
necklace.cpp:59:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i <= S.size(); i++) sort(vec[i].begin(), vec[i].end());
                  ~~^~~~~~~~~~~
necklace.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < T.size(); i++) {
                  ~~^~~~~~~~~~
necklace.cpp:63:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = i + 1; j <= T.size(); j++) {
                       ~~^~~~~~~~~~~
necklace.cpp:68:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (pos1 < vec[j - i].size() && vec[j - i][pos1].first == v) {
        ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 25 / 25
• Subtask 2: 0 / 20
• Subtask 3: 0 / 40