/*
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("unroll-loops")
*/
#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define len(x) ll(x.size())
#define eb emplace_back
#define PI acos(-1.0)
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define BIT(x,i) (1&((x)>>(i)))
#define MASK(x) (1LL<<(x))
#define task "tnc"
typedef long long ll;
typedef long double ld;
const ll INF=1e18;
const int maxn=1e6+5;
const int mod=1e9+7;
const int mo=998244353;
using pi=pair<ll,ll>;
using vi=vector<ll>;
using pii=pair<pair<ll,ll>,ll>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int n;
int ask(int l,int r){
cout<<"? "<<l<<" "<<r<<endl;
int x;
cin>>x;
return x;
}
signed main()
{
cin.tie(0),cout.tie(0)->sync_with_stdio(0);
//freopen(task".inp" , "r" , stdin);
//freopen(task".out" , "w" , stdout);
int n;
cin>>n;
int x=ask(1,n);
if(x!=1){
int d=ask(1,x);
if(d==x){
int l=1;
int r=x-1;
int ans;
while(l<=r){
int mid=(l+r)/2;
if(ask(mid,x)==x){
ans=mid;
l=mid+1;
}
else{
r=mid-1;
}
}
cout<<"! "<<ans<<endl;
return 0;
}
}
int l=x+1;
int r=n;
int ans;
while(l<=r){
int mid=(l+r)/2;
if(ask(x,mid)==x){
ans=mid;
r=mid-1;
}
else{
l=mid+1;
}
}
cout<<"! "<<ans<<endl;
return 0;
}
Compilation message
carnival.cpp: In function 'int main()':
carnival.cpp:80:17: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
80 | cout<<"! "<<ans<<endl;
| ^~~
carnival.cpp:63:25: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
63 | cout<<"! "<<ans<<endl;
| ^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
0 ms |
208 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |