Submission #647028

#	Time	Username	Problem	Language	Result	Execution time	Memory
647028		georgievskiy	parentrises (BOI18_parentrises)	C++17	50 / 100	21 ms	5312 KiB

parentrises

#include <bits/stdc++.h>
using namespace std;

bool check(string s, string a) {
	int b0 = 0, b1 = 0;
	for (int i = 0; i < s.size(); i++) {
		if (a[i] != 'B')
			b0 += (s[i] == '(') ? +1 : -1;
		if (a[i] != 'R')
			b1 += (s[i] == '(') ? +1 : -1;
		if (b0 < 0 || b1 < 0)
			return 0;
	}
	return b0 == 0 && b1 == 0;
}

void solve1() {
	string s;
	cin >> s;
	int n = s.size();
	string a(n, 'G');
	int b0 = 0, b1 = 0;
	for (int i = 0; i < n; i++) {
		if (s[i] == '(') {
			a[i] = 'G';
			b0++, b1++;
		} else {
			if (b0 >= b1) {
				a[i] = 'R';
				b0--;
			} else {
				a[i] = 'B';
				b1--;
			}
		}

		if (b0 < 0 || b1 < 0) {
			cout << "impossible\n";
			return;
		}
	}

	for (int i = n - 1; i >= 0 && (b0 > 0 || b1 > 0); i--) {
		if (s[i] == '(') {
			if (b0 >= b1)
				a[i] = 'B', b0--;
			else
				a[i] = 'R', b1--;
		} else {
			if (b0 > 0 && a[i] == 'B')
				a[i] = 'G', b0--;
			else if (b1 > 0 && a[i] == 'R')
				a[i] = 'G', b1--;
		}
		assert(b0 >= 0 && b1 >= 0);
	}

	if (check(s, a))
		cout << a << "\n";
	else
		cout << "impossible\n";
}

void solve2() {}

int main() {
	 ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int p, t;
	cin >> p >> t;
	while (t--) {
		if (p == 1)
			solve1();
		else
			solve2();
	}
	return 0;
}

Compilation message (stderr)

parentrises.cpp: In function 'bool check(std::string, std::string)':
parentrises.cpp:6:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    6 |  for (int i = 0; i < s.size(); 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