#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
const int mxn = 2e6+10;
int n;
string s;
string ans;
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>n>>s;
if(n%2==0){
cout<<"NOT POSSIBLE\n";
return 0;
}
string ts = s.substr(0,n/2);
int pt = 0;
for(int i = n/2;i<n;i++){
if(pt != ts.size()&&s[i] == ts[pt])pt++;
}
if(pt == ts.size())ans = ts;
ts = s.substr(n-n/2,n/2);
pt = 0;
for(int i = 0;i<=n/2;i++){
if(pt != ts.size()&&ts[pt] == s[i])pt++;
}
if(pt == ts.size()){
if(pt =!ans.empty()&&ans != ts){
cout<<"NOT UNIQUE\n";
return 0;
}
ans = ts;
}
cout<<(ans.empty()?"NOT POSSIBLE":ans)<<'\n';
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:27:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
27 | if(pt != ts.size()&&s[i] == ts[pt])pt++;
| ~~~^~~~~~~~~~~~
friends.cpp:29:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
29 | if(pt == ts.size())ans = ts;
| ~~~^~~~~~~~~~~~
friends.cpp:33:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
33 | if(pt != ts.size()&&ts[pt] == s[i])pt++;
| ~~~^~~~~~~~~~~~
friends.cpp:35:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | if(pt == ts.size()){
| ~~~^~~~~~~~~~~~
friends.cpp:36:9: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
36 | if(pt =!ans.empty()&&ans != ts){
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
1 ms |
348 KB |
Output is correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
348 KB |
Output is correct |
| 7 |
Correct |
0 ms |
348 KB |
Output is correct |
| 8 |
Correct |
1 ms |
348 KB |
Output is correct |
| 9 |
Correct |
1 ms |
348 KB |
Output is correct |
| 10 |
Correct |
0 ms |
348 KB |
Output is correct |
| 11 |
Correct |
0 ms |
348 KB |
Output is correct |
| 12 |
Correct |
0 ms |
348 KB |
Output is correct |
| 13 |
Correct |
1 ms |
348 KB |
Output is correct |
| 14 |
Correct |
0 ms |
348 KB |
Output is correct |
| 15 |
Correct |
1 ms |
348 KB |
Output is correct |
| 16 |
Correct |
0 ms |
348 KB |
Output is correct |
| 17 |
Correct |
1 ms |
348 KB |
Output is correct |
| 18 |
Correct |
0 ms |
348 KB |
Output is correct |
| 19 |
Correct |
0 ms |
348 KB |
Output is correct |
| 20 |
Correct |
0 ms |
344 KB |
Output is correct |
| 21 |
Correct |
0 ms |
348 KB |
Output is correct |
| 22 |
Correct |
0 ms |
348 KB |
Output is correct |
| 23 |
Correct |
1 ms |
348 KB |
Output is correct |
| 24 |
Correct |
0 ms |
348 KB |
Output is correct |
| 25 |
Correct |
1 ms |
348 KB |
Output is correct |
| 26 |
Correct |
1 ms |
348 KB |
Output is correct |
| 27 |
Correct |
0 ms |
456 KB |
Output is correct |
| 28 |
Correct |
0 ms |
600 KB |
Output is correct |
| 29 |
Correct |
0 ms |
348 KB |
Output is correct |
| 30 |
Correct |
0 ms |
348 KB |
Output is correct |
| 31 |
Correct |
0 ms |
344 KB |
Output is correct |
| 32 |
Correct |
0 ms |
344 KB |
Output is correct |
| 33 |
Correct |
0 ms |
348 KB |
Output is correct |
| 34 |
Correct |
1 ms |
348 KB |
Output is correct |
| 35 |
Correct |
0 ms |
348 KB |
Output is correct |
| 36 |
Correct |
0 ms |
348 KB |
Output is correct |
| 37 |
Correct |
0 ms |
348 KB |
Output is correct |
| 38 |
Correct |
0 ms |
456 KB |
Output is correct |
| 39 |
Correct |
0 ms |
348 KB |
Output is correct |
| 40 |
Correct |
0 ms |
344 KB |
Output is correct |
| 41 |
Correct |
0 ms |
348 KB |
Output is correct |
| 42 |
Correct |
0 ms |
344 KB |
Output is correct |
| 43 |
Correct |
0 ms |
348 KB |
Output is correct |
| 44 |
Correct |
1 ms |
348 KB |
Output is correct |
| 45 |
Correct |
1 ms |
348 KB |
Output is correct |
| 46 |
Correct |
1 ms |
348 KB |
Output is correct |
| 47 |
Correct |
0 ms |
348 KB |
Output is correct |
| 48 |
Correct |
0 ms |
348 KB |
Output is correct |
| 49 |
Correct |
0 ms |
348 KB |
Output is correct |
| 50 |
Correct |
1 ms |
348 KB |
Output is correct |
| 51 |
Correct |
1 ms |
348 KB |
Output is correct |
| 52 |
Correct |
0 ms |
348 KB |
Output is correct |
| 53 |
Correct |
0 ms |
348 KB |
Output is correct |
| 54 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
7 ms |
8180 KB |
Output is correct |
| 2 |
Correct |
7 ms |
8184 KB |
Output is correct |
| 3 |
Correct |
8 ms |
8252 KB |
Output is correct |
| 4 |
Correct |
7 ms |
8188 KB |
Output is correct |
| 5 |
Correct |
7 ms |
8188 KB |
Output is correct |
| 6 |
Correct |
4 ms |
4352 KB |
Output is correct |
| 7 |
Correct |
7 ms |
8184 KB |
Output is correct |
| 8 |
Correct |
5 ms |
6400 KB |
Output is correct |
| 9 |
Correct |
6 ms |
7488 KB |
Output is correct |
| 10 |
Correct |
6 ms |
7480 KB |
Output is correct |
| 11 |
Correct |
5 ms |
5116 KB |
Output is correct |
| 12 |
Correct |
1 ms |
348 KB |
Output is correct |
| 13 |
Correct |
0 ms |
348 KB |
Output is correct |
| 14 |
Correct |
1 ms |
348 KB |
Output is correct |
| 15 |
Correct |
0 ms |
348 KB |
Output is correct |
| 16 |
Correct |
1 ms |
348 KB |
Output is correct |
| 17 |
Correct |
0 ms |
344 KB |
Output is correct |
| 18 |
Correct |
0 ms |
348 KB |
Output is correct |
| 19 |
Correct |
1 ms |
600 KB |
Output is correct |
| 20 |
Correct |
0 ms |
348 KB |
Output is correct |
| 21 |
Correct |
1 ms |
344 KB |
Output is correct |
| 22 |
Correct |
1 ms |
344 KB |
Output is correct |
| 23 |
Correct |
0 ms |
348 KB |
Output is correct |
| 24 |
Correct |
0 ms |
348 KB |
Output is correct |
| 25 |
Correct |
0 ms |
348 KB |
Output is correct |
| 26 |
Correct |
0 ms |
348 KB |
Output is correct |
| 27 |
Correct |
0 ms |
348 KB |
Output is correct |
| 28 |
Correct |
0 ms |
348 KB |
Output is correct |
| 29 |
Correct |
0 ms |
348 KB |
Output is correct |
| 30 |
Correct |
1 ms |
344 KB |
Output is correct |
| 31 |
Correct |
0 ms |
348 KB |
Output is correct |
| 32 |
Correct |
0 ms |
348 KB |
Output is correct |
| 33 |
Correct |
1 ms |
344 KB |
Output is correct |
| 34 |
Correct |
0 ms |
356 KB |
Output is correct |
| 35 |
Correct |
1 ms |
360 KB |
Output is correct |
| 36 |
Correct |
0 ms |
360 KB |
Output is correct |
| 37 |
Correct |
1 ms |
608 KB |
Output is correct |
| 38 |
Correct |
0 ms |
464 KB |
Output is correct |
| 39 |
Correct |
0 ms |
360 KB |
Output is correct |
| 40 |
Correct |
0 ms |
360 KB |
Output is correct |
| 41 |
Correct |
1 ms |
360 KB |
Output is correct |
| 42 |
Correct |
0 ms |
352 KB |
Output is correct |
| 43 |
Correct |
0 ms |
360 KB |
Output is correct |
| 44 |
Correct |
0 ms |
360 KB |
Output is correct |
| 45 |
Correct |
1 ms |
756 KB |
Output is correct |
| 46 |
Correct |
1 ms |
348 KB |
Output is correct |
| 47 |
Correct |
1 ms |
348 KB |
Output is correct |
| 48 |
Correct |
0 ms |
456 KB |
Output is correct |
| 49 |
Correct |
0 ms |
348 KB |
Output is correct |
| 50 |
Correct |
0 ms |
348 KB |
Output is correct |
| 51 |
Correct |
1 ms |
348 KB |
Output is correct |
| 52 |
Correct |
0 ms |
452 KB |
Output is correct |
| 53 |
Correct |
0 ms |
344 KB |
Output is correct |
| 54 |
Correct |
0 ms |
348 KB |
Output is correct |
