Submission #745436

#	Time	Username	Problem	Language	Result	Execution time	Memory
745436		Alexandruabcde	Match (CEOI16_match)	C++14	37 / 100	2061 ms	952 KiB

match

#include <bits/stdc++.h>

using namespace std;

constexpr int NMAX = 1e5 + 5;
constexpr int SIGMAX = 26;

bool exist;

int sp[NMAX];
char ans[NMAX];

void Precompute (string S) {
    deque <char> D;
    for (int i = 0; i < S.size(); ++ i ) {
        if (D.empty() || D.back() != S[i]) {
            D.push_back(S[i]);
        }
        else {
            D.pop_back();
        }
    }

    exist = D.empty();
}

int pos[SIGMAX];
int bef[NMAX];

void Solve (string S) {
    for (int i = 0; i < SIGMAX; ++ i )
        pos[i] = -1;

    for (int i = 0; i < S.size(); ++ i ) {
        bef[i] = pos[S[i] - 'a'];

        pos[S[i] - 'a'] = i;
    }

    for (int i = 0; i < S.size(); ++ i ) {
        if (ans[i] == ')') continue;

        deque <char> D;
        int last = -1;

        for (int j = i+1; j < S.size(); ++ j ) {
            if (ans[j] == ')') {
                if (D.empty() || D.back() != S[j])
                    break;

                D.pop_back();
                continue;
            }

            if (D.empty() || D.back() != S[j]) {
                if (D.empty() && S[i] == S[j])
                    last = j;

                D.push_back(S[j]);
            }
            else {
                D.pop_back();
            }
        }

        ans[i] = '(';
        ans[last] = ')';
    }

    for (int i = 0; i < S.size(); ++ i )
        cout << ans[i];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    string S;
    cin >> S;

    Precompute(S);

    if (!exist) {
        cout << -1 << '\n';
        return 0;
    }

    Solve(S);

    return 0;
}

Compilation message (stderr)

match.cpp: In function 'void Precompute(std::string)':
match.cpp:15:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for (int i = 0; i < S.size(); ++ i ) {
      |                     ~~^~~~~~~~~~
match.cpp: In function 'void Solve(std::string)':
match.cpp:34:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |     for (int i = 0; i < S.size(); ++ i ) {
      |                     ~~^~~~~~~~~~
match.cpp:40:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for (int i = 0; i < S.size(); ++ i ) {
      |                     ~~^~~~~~~~~~
match.cpp:46:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |         for (int j = i+1; j < S.size(); ++ j ) {
      |                           ~~^~~~~~~~~~
match.cpp:70:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for (int i = 0; i < S.size(); ++ i )
      |                     ~~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 27 / 27
• Subtask 3: 0 / 63