Submission #1188690

#	Time	Username	Problem	Language	Result	Execution time	Memory
1188690		cpdreamer	Zagrade (COI20_zagrade)	C++20	0 / 100	3080 ms	664 KiB

zagrade

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
void file(){
    freopen("input.txt.txt","r",stdin);
    freopen("output.txt.txt","w",stdout);
}
const ll mod=(ll)1e9+7;
#define V vector
#define P pair
#define F first
#define S second
#define all(v) v.begin(),v.end()
#define pb push_back

int ask(int l,int r){
    cout<<"? "<<l<<" "<<r<<endl;
    cout.flush();
    int x;
    cin>>x;
    return x;
}
void solve() {
    int n,q;
    cin>>n>>q;
    V<int>vp(n+1);
    vp[1]=1;
    vp[n]=-1;
    int l=1;
    int sum=1;
    for(int i=2;i<n;i++){
        if(vp[i-1]==1){
            int x=ask(i-1,i);
            if(x==1){
                vp[i]=-1;
            }
            else{
                vp[i]=1;
            }
        }
        else{
            if(l==1){
                vp[i]=1;
            }
            else{
                int x=ask(l-1,i);
                if(x==1){
                    vp[i]=-1;
                }
                else
                    vp[i]=1;
            }
        }
        sum+=vp[i];
         if(sum>0) {
            while (l < i && (vp[l-1] != 1 || sum > 0)) {
                sum -= vp[l+1];
                l++;
            }
        }
        else {
            while (l > 1 && (vp[l-1] != 1 || sum < 0)) {
                sum += vp[l-1];
                l--;
            }
        }
    }
    string s;
    for(int i=1;i<=n;i++){
        if(vp[i]==1)
            s+='(';
        else
            s+=')';
    }
    cout<<"! "<<s<<endl;
}
int main(){
  // file();
    solve();
}

Compilation message (stderr)

zagrade.cpp: In function 'void file()':
zagrade.cpp:5:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 |     freopen("input.txt.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
zagrade.cpp:6:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    6 |     freopen("output.txt.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 7
• Subtask 3: 0 / 57
• Subtask 4: 0 / 22