Submission #613320

#	Time	Username	Problem	Language	Result	Execution time	Memory
613320		drdilyor	Match (CEOI16_match)	C++17	100 / 100	51 ms	56576 KiB

match

#include <bits/stdc++.h>
#ifdef ONPC
    #include "t_debug.cpp"
#else
    #define debug(...) 42
#endif
#define sz(a) ((int)(a).size())
using namespace std;
using ll = long long;
const int INF = 1e9;
const ll INFL = 1e18;
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937 rng(RANDOM);
template<typename T, typename U> istream& operator>>(istream& is, pair<T, U>& p) { return is >> p.first >> p.second; }
const int N = 2e5, LOGN = 17, MOD = 1e9+7;

string solve(const string& s) {
    int n = s.size();
    string res(n, '?');
    vector<vector<int>> prev(n, vector<int>(128, -1));

    for (int i = 0; i < n; i++) {
        if (i) {
            int j = prev[i-1][s[i]] - 1;
            if (j >= 0) prev[i] = prev[j];
        }
        prev[i][s[i]] = i;
    }

    vector<char> cur;
    for (int i = 0; i < n; i++) {
        if (!cur.empty() && cur.back() == s[i]) {
            cur.pop_back();
        } else {
            cur.push_back(s[i]);
        }
    }
    if (!cur.empty()) return "-1";

    function<void(int,int)> construct = [&](int beg, int end) {
        if (beg > end) return;
        if (s[beg] == s[end]) {
            res[beg] = '(';
            res[end] = ')';
            construct(beg+1, end-1);
            return;
        }
        int j = prev[end][s[beg]];
        debug(s, beg, end, j);
        res[beg] = '(';
        res[j] = ')';
        construct(beg+1, j-1);
        construct(j+1, end);
    };
    construct(0, n-1);
    return res;
}

string solve_2(const string& s) {
    int n = s.size();
    string res(n, '?');
    function<bool(int)> brute = [&](int i) {
        if (i < n) {
            res[i] = '(';
            if (brute(i+1)) return true;
            res[i] = ')';
            return brute(i+1);
        } else {
            vector<int> matching(n, -1);
            vector<int> cur;
            for (int i = 0; i < n; i++) {
                if (res[i] == '(') {
                    cur.push_back(i);
                } else {
                    if (cur.empty()) return false;
                    if (s[i] != s[cur.back()]) return false; 
                    cur.pop_back();
                }
            }
            return cur.empty();
        }
    };
    return brute(0) ? res : "-1";
}

signed main() {
    int t = 1;
    #ifdef ONPC
    cin >> t;
    #endif
    while (t-- && cin) {
        string s; cin >> s;
        if (!cin) break;
        #ifdef ONPC
        cout << "Case " << s << '\n';
        string res1 = solve(s), res2 = solve_2(s);
        cout << res1 << endl;
        if (res1 != res2) {
            cout << res2 << endl;
            cout << "Case " << s << '\n';
            assert(false);
        }
        #else
        cout << solve(s);
#endif
    }
    return 0;
}

/*
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 ███▒▒███ ▒▒███▒▒███ ███▒▒███ ▒▒███  ▒███ ▒▒███ ▒███  ███▒▒███▒▒███▒▒███
▒███ ▒███  ▒███ ▒▒▒ ▒███ ▒███  ▒███  ▒███  ▒███ ▒███ ▒███ ▒███ ▒███ ▒▒▒ 
▒███ ▒███  ▒███     ▒███ ▒███  ▒███  ▒███  ▒███ ▒███ ▒███ ▒███ ▒███     
▒▒████████ █████    ▒▒████████ █████ █████ ▒▒███████ ▒▒██████  █████    
 ▒▒▒▒▒▒▒▒ ▒▒▒▒▒      ▒▒▒▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒   ▒▒▒▒▒███  ▒▒▒▒▒▒  ▒▒▒▒▒     
                                            ███ ▒███                    
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*/

Compilation message (stderr)

match.cpp: In lambda function:
match.cpp:5:24: warning: statement has no effect [-Wunused-value]
    5 |     #define debug(...) 42
      |                        ^~
match.cpp:49:9: note: in expansion of macro 'debug'
   49 |         debug(s, beg, end, j);
      |         ^~~~~

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