Submission #365451

#	Time	Username	Problem	Language	Result	Execution time	Memory
365451		lookcook	parentrises (BOI18_parentrises)	C++17	50 / 100	66 ms	4360 KiB

parentrises

#include <bits/stdc++.h>

#define int long long

using namespace std;

const int maxn = 1000005;
char res[maxn];

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int p, t;
    cin >> p >> t;
    if (p == 1) {
        while (t--) {
            string s;
            cin >> s;
            bool ok = true;
            bool turn = true;
            int sr = 0;
            int sb = 0;
            for (int i = 0; i < s.length(); i++) {
                if (s[i] == '(') {
                    res[i] = 'G';
                    sr++;
                    sb++;
                } else {
                    if (turn) {
                        res[i] = 'R';
                        sr--;
                    } else {
                        res[i] = 'B';
                        sb--;
                    }
                    turn = !turn;
                }
                if (sr < 0 || sb < 0) ok = false;
            }
            if (sb>sr) {
                for (int i = s.length()-1; i >= 0; i--) {
                    if (s[i] == '(') {
                        res[i] = 'R';
                        break;
                    }
                    if (s[i] == ')' && res[i] == 'R') {
                        res[i] = 'G';
                        break;
                    }
                }
            }
            sr = 0;
            sb = 0;
            for (int i = 0; i < s.length(); i++) {
                if (s[i] == ')') {
                    if (res[i] == 'G') {
                        sr--;
                        sb--;
                    }
                    if (res[i] == 'R') sr--;
                    if (res[i] == 'B') sb--;
                } else {
                    if (res[i] == 'G') {
                        sr++;
                        sb++;
                    }
                    if (res[i] == 'R') sr++;
                    if (res[i] == 'B') sb++;
                }
                if (sr < 0 || sb < 0) ok = false;
            }
            for (int i = s.length()-1; i >= 0; i--) {
                if (s[i] == '(' && res[i] == 'G') {
                    if (sr>=sb && sr>0) { // maybe swap order?
                        sr--;
                        res[i] = 'B';
                    } else if (sb > 0) {
                        sb--;
                        res[i] = 'R';
                    }
                }
                if (s[i] == ')') {
                    if (res[i] == 'R' && sb>0) {
                        res[i] = 'G';
                        sb--;
                    } else if (res[i] == 'B' && sr>0) {
                        res[i] = 'G';
                        sr--;
                    }
                }
            }
            sr = 0;
            sb = 0;
            for (int i = 0; i < s.length(); i++) {
                if (s[i] == ')') {
                    if (res[i] == 'G') {
                        sr--;
                        sb--;
                    }
                    if (res[i] == 'R') sr--;
                    if (res[i] == 'B') sb--;
                } else {
                    if (res[i] == 'G') {
                        sr++;
                        sb++;
                    }
                    if (res[i] == 'R') sr++;
                    if (res[i] == 'B') sb++;
                }
                if (sr < 0 || sb < 0) ok = false;
            }
            if (ok && sr==0&&sb==0) {
                for (int i = 0; i < s.length(); i++) cout << res[i];
                cout << '\n';
            } else {
                cout << "impossible\n";
            }
        }
    }
}

Compilation message (stderr)

parentrises.cpp: In function 'int main()':
parentrises.cpp:23:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |             for (int i = 0; i < s.length(); i++) {
      |                             ~~^~~~~~~~~~~~
parentrises.cpp:54:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |             for (int i = 0; i < s.length(); i++) {
      |                             ~~^~~~~~~~~~~~
parentrises.cpp:94:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |             for (int i = 0; i < s.length(); i++) {
      |                             ~~^~~~~~~~~~~~
parentrises.cpp:113:35: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |                 for (int i = 0; i < s.length(); i++) cout << res[i];
      |                                 ~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 6 / 6
• Subtask 4: 28 / 28
• Subtask 5: 0 / 6
• Subtask 6: 0 / 16
• Subtask 7: 0 / 28