#include<bits/stdc++.h>
using namespace std;
int n;
int p[100005];
bool query(int le, int ri)
{
if(le<1 || ri>n || le>ri)
return 0;
if(le==ri)
return 1;
int aux;
cout<<"? "<<le<<" "<<ri<<endl;
cin>>aux;
return aux;
}
signed main()
{
cin>>n;
int le=1,ri=1,mxm=1;
for(int i=1;i<n;i++)
{
p[i] = max(0, min(ri-i, p[le + (ri-i)]));
while(query(i-p[i],i+p[i]))
p[i]++;
if(i+p[i] > ri)
{
le = i-p[i];
ri = i+p[i];
}
mxm = max(mxm, 2*p[i]-1);
}
le=1;
ri=1;
for(int i=1;i<n;i++)
{
p[i] = max(0, min(ri-i-1, p[le+(ri-i)-1]));
while(query(i-p[i],i+1+p[i]))
p[i]++;
if(i+1+p[i] > ri)
{
le = i-p[i];
ri = i+1+p[i];
}
mxm = max(mxm, 2*p[i]);
}
cout<<"! "<<mxm<<endl;
return 0;
}
/**
neven
1 2 3 4 5 6 7 8 9
l r
a b c b a
1 2 3 4 5 6 7 8 9
l r
a b c c b a
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
149 ms |
700 KB |
Output is correct |
2 |
Correct |
75 ms |
592 KB |
Output is correct |
3 |
Correct |
63 ms |
592 KB |
Output is correct |
4 |
Correct |
181 ms |
600 KB |
Output is correct |
5 |
Correct |
149 ms |
696 KB |
Output is correct |
6 |
Correct |
148 ms |
676 KB |
Output is correct |
7 |
Correct |
138 ms |
600 KB |
Output is correct |
8 |
Correct |
119 ms |
592 KB |
Output is correct |
9 |
Correct |
144 ms |
944 KB |
Output is correct |
10 |
Correct |
89 ms |
684 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
149 ms |
700 KB |
Output is correct |
2 |
Correct |
75 ms |
592 KB |
Output is correct |
3 |
Correct |
63 ms |
592 KB |
Output is correct |
4 |
Correct |
181 ms |
600 KB |
Output is correct |
5 |
Correct |
149 ms |
696 KB |
Output is correct |
6 |
Correct |
148 ms |
676 KB |
Output is correct |
7 |
Correct |
138 ms |
600 KB |
Output is correct |
8 |
Correct |
119 ms |
592 KB |
Output is correct |
9 |
Correct |
144 ms |
944 KB |
Output is correct |
10 |
Correct |
89 ms |
684 KB |
Output is correct |
11 |
Runtime error |
1175 ms |
1120 KB |
Execution killed with signal 13 |
12 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1263 ms |
1476 KB |
Execution killed with signal 13 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
149 ms |
700 KB |
Output is correct |
2 |
Correct |
75 ms |
592 KB |
Output is correct |
3 |
Correct |
63 ms |
592 KB |
Output is correct |
4 |
Correct |
181 ms |
600 KB |
Output is correct |
5 |
Correct |
149 ms |
696 KB |
Output is correct |
6 |
Correct |
148 ms |
676 KB |
Output is correct |
7 |
Correct |
138 ms |
600 KB |
Output is correct |
8 |
Correct |
119 ms |
592 KB |
Output is correct |
9 |
Correct |
144 ms |
944 KB |
Output is correct |
10 |
Correct |
89 ms |
684 KB |
Output is correct |
11 |
Runtime error |
1175 ms |
1120 KB |
Execution killed with signal 13 |
12 |
Halted |
0 ms |
0 KB |
- |