Submission #745451

#	Time	Username	Problem	Language	Result	Execution time	Memory
745451		Alexandruabcde	Match (CEOI16_match)	C++14	37 / 100	2057 ms	15872 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];
string S;

void Precompute () {
    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 (int st, int dr) {
    if (st > dr) return;

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

    for (int j = st+1; j <= dr; ++ 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[st] == S[j])
                last = j;

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

    ans[st] = '(';
    ans[last] = ')';

    Solve(st+1, last-1);
    Solve(last+1, dr);
}

void Solve () {
    Solve(0, S.size()-1);

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

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

    cin >> S;

    Precompute();

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

    Solve();

    return 0;
}

Compilation message (stderr)

match.cpp: In function 'void Precompute()':
match.cpp:16:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for (int i = 0; i < S.size(); ++ i ) {
      |                     ~~^~~~~~~~~~
match.cpp: In function 'void Solve()':
match.cpp:67:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for (int i = 0; i < S.size(); ++ i )
      |                     ~~^~~~~~~~~~

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