Submission #712497

#	Time	Username	Problem	Language	Result	Execution time	Memory
712497		noedit	Zagrade (COI20_zagrade)	C++17	100 / 100	897 ms	1344 KiB

zagrade

#include <bits/stdc++.h>
//#include <quadmath.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//#define sz(x) (int)x.size()
//#define sqr(x) x*x
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.1,sse4.2,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("fast-math")
using namespace std;
//using namespace __gnu_pbds;

#define int long long
//#define ld long double
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;

bool ask(int l, int r)
{
    cout << "? " << l << " " << r << endl;
    int b;
    cin >> b;
    return b;
}

const int MAXN = 1e5 + 10;

bool check[MAXN];
char ans[MAXN];
int lt[MAXN], rt[MAXN];

void solve()
{
    int n, k;
    cin >> n >> k;
    stack<int> st;
    fill(ans, ans + n + 1, '#');
    for (int i = 1; i <= n; i++)
    {
        if (st.empty())
        {
            st.push(i);
        }
        else
        {
            int res = ask(st.top(), i);
            if (res)
            {
                ans[st.top()] = '(';
                ans[i] = ')';
                st.pop();
            }
            else
            {
                st.push(i);
            }
        }
    }
    int cnt = 0;
    for (int i = 1; i <= n; i++)
    {
        if (ans[i] == '#')
        {
            if (cnt < st.size() / 2) ans[i] = ')', cnt++;
            else ans[i] = '(';
        }
    }
    cout << "! ";
    for (int i = 1; i <= n; i++) cout << ans[i];
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    t = 1;
    //cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}
/*
4 2 4
3 1 1 10
9 2 2 4
7 2 5 7
4 1 8 10
5 3
5 6
5 9
1 10
*/

/*
2 1 3
1 1 1 4
1 1 2 6
1 3
1 5
1 7
*/

/*
1 1 1
100000000 1 1 1
1 1
*/

/*
4 4
1 2 1 3
1 1
1 2
1 3
1 4
*/

Compilation message (stderr)

zagrade.cpp: In function 'void solve()':
zagrade.cpp:67:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::stack<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |             if (cnt < st.size() / 2) ans[i] = ')', cnt++;
      |                 ~~~~^~~~~~~~~~~~~~~

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