Submission #641591

#	Time	Username	Problem	Language	Result	Execution time	Memory
641591		bonk	Zagrade (COI20_zagrade)	C++14	100 / 100	1002 ms	960 KiB

zagrade

#include <bits/stdc++.h>

using namespace std;

int ask(int a, int b){
    cout << "? " << a << " " << b << endl;
    int ret; cin >> ret;

    return ret;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int n, q; cin >> n >> q;
    vector<char>ans(n + 1, '#');
    stack<int>st;

    int cnt = 0;

    for(int i = 1; i <= n; i++){
        if(st.empty()){
            st.push(i);
            continue;
        }

        int x = st.top(); 
        if(ask(x, i)){
            cnt += 2;
            ans[x] = '(';
            ans[i] = ')';
            st.pop();
        } else{
            st.push(i);
        }
    }

    int unused = n - cnt;
    int tmp = unused;

    cout << "! ";

    for(int i = 1; i <= n; i++){
        if(ans[i] == '#'){
            if(tmp > unused/2) ans[i] = ')';
            else ans[i] = '(';
            tmp--;
        } 

        cout << ans[i];
    }

    cout << endl;

    return 0;
}

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