백준 1547번 C++ 풀이

#include <iostream>
#include <queue>
using namespace std;
bool buffer[3];
void swap(int a, int b){
    int temp = buffer[a];
    buffer[a] = buffer[b];
    buffer[b] = temp;
}
int main(int argc, const char * argv[]) {
    cin.tie(NULL);
    ios::sync_with_stdio(false);
    int n;
    buffer[0] = true;
    cin >> n;
    for (int i = 0; i < n ; i++){
        int a, b;
        cin >> a >> b;
        swap(a-1, b-1);
    }
    for (int i = 0 ; i< 3; i++){
        if(buffer[i]) cout<< i+1;
    }
    return 0;

}