Submission #821495

#	Time	Username	Problem	Language	Result	Execution time	Memory
821495		stefanopulos	Zagrade (COI20_zagrade)	C++17	100 / 100	1185 ms	1756 KiB

zagrade

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ldb;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;

#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for(auto& a : x)
 
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 100005; 

int n, q;

int L[mxN];
int R[mxN];

int res[mxN];

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


int main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> n >> q;

    ff(i,1,n){
        L[i] = i - 1;
        R[i] = i + 1;
    }

    int l = 1; int br = 0;
    while(1){
        
        bool ok = 0;
        ff(i,l,n - 1){
            if(!res[i] && R[i] <= n && ask(i, R[i])){
                res[i] = 1; res[R[i]] = 2; br += 2;

                int j = R[i];
                R[L[i]] = R[j];
                L[R[j]] = L[i];
                l = max(1, L[i]);

                ok = 1; 
                break;
            }
        }

        if(!ok)break;

    }

    int ost = (n - br) / 2;
    ff(i,1,n){
        if(res[i])continue;
        if(ost > 0)res[i] = 2, ost -= 1;
        else res[i] = 1;
    }

    cout << "! ";
    ff(i,1,n)cout << (res[i] == 1 ? '(' : ')');
    cout << endl;

    return 0;
}
/*



// probati bojenje sahovski
*/
 
 
 
 
 

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