#include <bits/stdc++.h>
using namespace std;
#define TRACE(x) cerr << #x << " :: " << x << endl
#define _ << " " <<
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(),(x).end()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for (int i=(a);i>=(b);--i)
const int mxN = 2e6+5;
int N, cnt;
string S, a1, a2;
string solve() {
int m = N/2, l = -1, r = m+1, ok;
ok = 1;
FOR(i,0,m-1){
ok &= S[i] == S[i+m+1];
if (ok) l = i;
else break;
}
ok = 1;
RFOR(i,m,0){
ok &= S[i] == S[i+m];
if (ok) r = i;
else break;
}
TRACE(l _ r);
if (l+2 >= r) return S.substr(m+1,N-m-1);
return "";
}
int main() {
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> N >> S;
a1 = solve();
reverse(ALL(S));
a2 = solve();
reverse(ALL(a2));
if (!SZ(a1) && !SZ(a2)) cout << "NOT POSSIBLE" << '\n';
else if (SZ(a1) && SZ(a2) && a1 != a2) cout << "NOT UNIQUE" << '\n';
else cout << (SZ(a1) ? a1 : a2) << '\n';
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
204 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
204 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
208 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
204 KB |
Output is correct |
14 |
Correct |
1 ms |
204 KB |
Output is correct |
15 |
Correct |
1 ms |
264 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
204 KB |
Output is correct |
18 |
Correct |
1 ms |
204 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
20 |
Correct |
1 ms |
208 KB |
Output is correct |
21 |
Correct |
1 ms |
204 KB |
Output is correct |
22 |
Correct |
1 ms |
204 KB |
Output is correct |
23 |
Correct |
1 ms |
204 KB |
Output is correct |
24 |
Correct |
1 ms |
204 KB |
Output is correct |
25 |
Correct |
1 ms |
204 KB |
Output is correct |
26 |
Correct |
1 ms |
204 KB |
Output is correct |
27 |
Correct |
1 ms |
204 KB |
Output is correct |
28 |
Correct |
1 ms |
204 KB |
Output is correct |
29 |
Correct |
1 ms |
204 KB |
Output is correct |
30 |
Correct |
1 ms |
204 KB |
Output is correct |
31 |
Correct |
1 ms |
204 KB |
Output is correct |
32 |
Correct |
1 ms |
204 KB |
Output is correct |
33 |
Correct |
1 ms |
204 KB |
Output is correct |
34 |
Correct |
1 ms |
204 KB |
Output is correct |
35 |
Correct |
1 ms |
204 KB |
Output is correct |
36 |
Correct |
1 ms |
204 KB |
Output is correct |
37 |
Correct |
1 ms |
204 KB |
Output is correct |
38 |
Correct |
1 ms |
204 KB |
Output is correct |
39 |
Correct |
1 ms |
204 KB |
Output is correct |
40 |
Correct |
1 ms |
204 KB |
Output is correct |
41 |
Correct |
1 ms |
204 KB |
Output is correct |
42 |
Correct |
1 ms |
204 KB |
Output is correct |
43 |
Correct |
1 ms |
204 KB |
Output is correct |
44 |
Correct |
1 ms |
204 KB |
Output is correct |
45 |
Correct |
1 ms |
204 KB |
Output is correct |
46 |
Correct |
1 ms |
208 KB |
Output is correct |
47 |
Correct |
1 ms |
204 KB |
Output is correct |
48 |
Correct |
1 ms |
204 KB |
Output is correct |
49 |
Correct |
1 ms |
204 KB |
Output is correct |
50 |
Correct |
1 ms |
204 KB |
Output is correct |
51 |
Correct |
1 ms |
204 KB |
Output is correct |
52 |
Correct |
1 ms |
204 KB |
Output is correct |
53 |
Correct |
1 ms |
204 KB |
Output is correct |
54 |
Correct |
1 ms |
208 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
9 ms |
4208 KB |
Output is correct |
2 |
Correct |
9 ms |
4208 KB |
Output is correct |
3 |
Correct |
9 ms |
4276 KB |
Output is correct |
4 |
Correct |
9 ms |
4208 KB |
Output is correct |
5 |
Correct |
9 ms |
4208 KB |
Output is correct |
6 |
Correct |
9 ms |
4336 KB |
Output is correct |
7 |
Correct |
14 ms |
7084 KB |
Output is correct |
8 |
Correct |
10 ms |
5524 KB |
Output is correct |
9 |
Correct |
9 ms |
5616 KB |
Output is correct |
10 |
Correct |
9 ms |
5552 KB |
Output is correct |
11 |
Correct |
7 ms |
3696 KB |
Output is correct |
12 |
Correct |
1 ms |
204 KB |
Output is correct |
13 |
Correct |
1 ms |
204 KB |
Output is correct |
14 |
Correct |
1 ms |
204 KB |
Output is correct |
15 |
Correct |
1 ms |
204 KB |
Output is correct |
16 |
Correct |
1 ms |
204 KB |
Output is correct |
17 |
Correct |
1 ms |
204 KB |
Output is correct |
18 |
Correct |
1 ms |
320 KB |
Output is correct |
19 |
Correct |
1 ms |
204 KB |
Output is correct |
20 |
Correct |
1 ms |
204 KB |
Output is correct |
21 |
Correct |
1 ms |
204 KB |
Output is correct |
22 |
Correct |
1 ms |
312 KB |
Output is correct |
23 |
Correct |
1 ms |
204 KB |
Output is correct |
24 |
Correct |
1 ms |
204 KB |
Output is correct |
25 |
Correct |
1 ms |
204 KB |
Output is correct |
26 |
Correct |
1 ms |
204 KB |
Output is correct |
27 |
Correct |
1 ms |
204 KB |
Output is correct |
28 |
Correct |
1 ms |
204 KB |
Output is correct |
29 |
Correct |
1 ms |
204 KB |
Output is correct |
30 |
Correct |
1 ms |
204 KB |
Output is correct |
31 |
Correct |
1 ms |
204 KB |
Output is correct |
32 |
Correct |
1 ms |
308 KB |
Output is correct |
33 |
Correct |
1 ms |
204 KB |
Output is correct |
34 |
Correct |
1 ms |
204 KB |
Output is correct |
35 |
Correct |
1 ms |
204 KB |
Output is correct |
36 |
Correct |
1 ms |
204 KB |
Output is correct |
37 |
Correct |
1 ms |
204 KB |
Output is correct |
38 |
Correct |
1 ms |
204 KB |
Output is correct |
39 |
Correct |
1 ms |
204 KB |
Output is correct |
40 |
Correct |
1 ms |
204 KB |
Output is correct |
41 |
Correct |
1 ms |
204 KB |
Output is correct |
42 |
Correct |
1 ms |
204 KB |
Output is correct |
43 |
Correct |
1 ms |
204 KB |
Output is correct |
44 |
Correct |
1 ms |
204 KB |
Output is correct |
45 |
Correct |
1 ms |
204 KB |
Output is correct |
46 |
Correct |
1 ms |
204 KB |
Output is correct |
47 |
Correct |
1 ms |
204 KB |
Output is correct |
48 |
Correct |
1 ms |
204 KB |
Output is correct |
49 |
Correct |
1 ms |
204 KB |
Output is correct |
50 |
Correct |
1 ms |
204 KB |
Output is correct |
51 |
Correct |
1 ms |
204 KB |
Output is correct |
52 |
Correct |
1 ms |
204 KB |
Output is correct |
53 |
Correct |
1 ms |
316 KB |
Output is correct |
54 |
Correct |
1 ms |
312 KB |
Output is correct |