Submission #781311

#	Time	Username	Problem	Language	Result	Execution time	Memory
781311		makanhulia	Zagrade (COI20_zagrade)	C++17	100 / 100	728 ms	1440 KiB

zagrade

# include <bits/stdc++.h>
# define int long long
# define vi vector<int>
# define pb push_back
# define pii pair<int, int>
# define fi first
# define se second
# define endl '\n'

using namespace std;

char ans[100005];

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

void solve() {
    int n, q;
    cin >> n >> q;
    stack<int> s;
    s.push(1);
    int cnt=0;
    for(int i=1; i<=n; i++) ans[i]='-';
    for(int i=2; i<=n; i++) {
        if(s.empty()) {
            s.push(i);
            continue;
        }
        if(ask(s.top(), i)) {
            ans[s.top()]='(';
            ans[i]=')';
            cnt++;
            s.pop();
        } else {
            s.push(i);
        }
    }
    int tmp=(n/2)-cnt;
    for(int i=1; i<=n; i++) {
        if(ans[i]=='-') {
            if(tmp>0) {
                ans[i]=')';
                tmp--;
            } else ans[i]='(';
        }
    }
    cout << "! ";
    for(int i=1; i<=n; i++) cout << ans[i];
    cout << endl << flush;
}
 
signed main() {
    solve();
}

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