Submission #640577

#	Time	Username	Problem	Language	Result	Execution time	Memory
640577		KindaNameless	Zagrade (COI20_zagrade)	C++14	100 / 100	892 ms	1192 KiB

zagrade

#include<algorithm>
#include<iostream>
#include<assert.h>
#include<iomanip>
#include<cstring>
#include<numeric>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<stack>
#include<deque>
#include<cmath>
#include<map>
#include<set>
using namespace std;

#define ll long long
#define ld long double

bool ask(int a, int b){
    cout << "? " << a << " " << b << "\n"; cout << flush;
    bool ret; cin >> ret;
    return ret;
}

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int N, Q; cin >> N >> Q;

    string s = "";
    vector<int> st;
    vector<bool> valid(N+1);

    for(int i = 1; i <= N; ++i){
        if(st.empty()){
            st.push_back(i);
            s += '(';
            continue;
        }

        bool q = ask(st.back(), i);

        if(q){
            valid[st.back()] = 1;
            valid[i] = 1;
            st.pop_back();
            s += ')';
        }
        else{
            st.push_back(i);
            s += '(';
        }
    }

    assert((int)st.size() % 2 == 0);

    for(int i = 0; i < (int)st.size()/2; ++i){
        s[st[i]-1] = ')';
    }

    cout << "! " << s << "\n"; cout << flush;

    return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 7 / 7
• Subtask 3: 57 / 57
• Subtask 4: 22 / 22