Submission #62104

#	Time	Username	Problem	Language	Result	Execution time	Memory
62104		gs14004	parentrises (BOI18_parentrises)	C++17	56 / 100	1063 ms	6668 KiB

parentrises

#include<bits/stdc++.h>
using namespace std;
using pi = pair<int, int>;
using lint = long long;
const int MAXN = 1000050;
 
bool det(string s){
	int qcnt = 0, pcnt = 0;
	int bcnt = 0;
	int numcnt = 0;
	for(int i=0; i<s.size(); i++){
		if(s[i] == '('){
			qcnt++;
			bcnt++;
		}
		else{
			if(bcnt > 0){
				bcnt--;
			}
			else{
				if(qcnt == pcnt) return 0;
				pcnt++;
			}
		}
	}
	bcnt = s.size() - qcnt - bcnt;
	if(bcnt < 0) return 0;
	for(int i=0; i<s.size(); i++){
		if(s[i] == '('){
			if(pcnt > 0){
				numcnt += 2;
				pcnt--;
			}
			else{
				numcnt += 1;
			}
		}
		else{
			if(bcnt == 0){
				numcnt -= 2;
			}
			else{
				bcnt--;
				numcnt -= 1;
			}
		}
		if(numcnt < 0) return 0;
	}
	return numcnt == 0;
}
 
int f(int n){
	int ans = 0;
	for(int i=0; i<(1<<n); i++){
		string s;
		for(int j=0; j<n; j++){
			if((i >> j) & 1) s.push_back('(');
			else s.push_back(')');
		}
		if(det(s)) ans++;
	}
	return ans;
}
 
string solve(string s){
	queue<int> que;
	string chk;
	int cnt = 0;
	chk.resize(s.size());
	for(int i=0; i<s.size(); i++){
		if(s[i] == '('){
			que.push(i);
			cnt++;
			chk[i] = '?';
		}
		else{
			if(cnt > 0){
				chk[i] = '!';
				cnt--;
			}
			else{
				if(que.empty()) return "impossible";
				int x = que.front();
				que.pop();
				chk[x] = 'G';
				chk[i] = '!';
			}
		}
	}
	for(int i=(int)s.size()-1; i>=0; i--){
		if(s[i] == ')' && cnt){
			chk[i] = 'G';
			cnt--;
		}
	}
	if(cnt > 0) return "impossible";
	int c0 = 0, c1 = 0;
	for(int i=0; i<s.size(); i++){
		if(s[i] == '('){
			if(chk[i] == 'G') cnt += 2;
			else{
				cnt++;
				if(cnt & 1) chk[i] = 'R';
				else chk[i] = 'B';
			}
			if(chk[i] != 'B') c0++;
			if(chk[i] != 'R') c1++;
		}
		else{
			if(chk[i] == 'G') cnt -= 2;
			else{
				if(cnt & 1) chk[i] = 'R';
				else chk[i] = 'B';
				cnt--;
			}
			if(chk[i] != 'B') c0--;
			if(chk[i] != 'R') c1--;
		}
		if(c0 < 0 || c1 < 0) return "impossible";
	}
	if(c0 == 0 && c1 == 0) return chk;
	else return "impossible";
}
 
int main(){
	char buf[MAXN];
	int p, t; cin >> p;
	if(p == 1){
		scanf("%d",&t);
		while(t--){
			scanf("%s",buf);
			string ans = buf;
			printf("%s\n", solve(buf).c_str());
		}
	}
	else{
		scanf("%d",&t);
		while(t--){
			int n; cin >> n;
			cout << f(n) << endl;
		}
	}
}

Compilation message (stderr)

parentrises.cpp: In function 'bool det(std::__cxx11::string)':
parentrises.cpp:11:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<s.size(); i++){
               ~^~~~~~~~~
parentrises.cpp:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<s.size(); i++){
               ~^~~~~~~~~
parentrises.cpp: In function 'std::__cxx11::string solve(std::__cxx11::string)':
parentrises.cpp:70:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<s.size(); i++){
               ~^~~~~~~~~
parentrises.cpp:98:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<s.size(); i++){
               ~^~~~~~~~~
parentrises.cpp: In function 'int main()':
parentrises.cpp:129:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&t);
   ~~~~~^~~~~~~~~
parentrises.cpp:131:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%s",buf);
    ~~~~~^~~~~~~~~~
parentrises.cpp:137:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&t);
   ~~~~~^~~~~~~~~

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