[백준 11723번 C/C++] 집합

[백준 11723번 C/C++] 집합

 

https://www.acmicpc.net/problem/11723

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해결전략

 

비트마스킹 Bitmasking

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정답 코드

 

#include <iostream>
using namespace std;
 
int m;
int answer;
 
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
 
	cin >> m;
	string input, int x;
	for (int i = 0; i < m; i++)
	{
		cin >> input;
 
		if (input == "add"){
			cin >> x;
			answer |= (1 << x);
		}
		else if (input == "remove"){
			cin >> x;
			answer &= ~(1 << x);
		}
		else if (input == "check") {
			cin >> x;
 
			if (answer & (1 << x)){
				cout << "1" << "\n";
			}
			else {
				cout << "0" << "\n";
			}
		}
		else if (input == "toggle") {
			cin >> x;
			answer ^= (1 << x);
		}
		else if (input == "all") {
			answer |= ((1 << 21) - 1);
		}
		else if (input == "empty") {
			//answer &= ~((1 << 21) - 1);
			answer = 0;
		}
	}
 
	return 0;
}

 

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