#include <bits/stdc++.h>
using namespace std;
char S[2000009];
bool A[1000009], B[1000009], LA[1000009], LB[1000009], RA[1000009], RB[1000009];
int N, h;
bool chk(int p) {
string s, t;
for(int i=1, j=1; i<=N; i++) {
if(i == p) continue;
if(j > h) s += S[i];
else t += S[i], ++j;
}
if(s == t) return 1;
return 0;
}
void putans(int p) {
for(int i=1, j=1; i<=N; i++) {
if(p != i && j <= h) {
printf("%c", S[i]);
++j;
}
}
exit(0);
}
int main() {
bool fl = 1;
scanf("%d %s", &N, S+1);
if(N%2 == 0) return !printf("NOT POSSIBLE");
h = N/2;
for(int i=1; i<=N; i++) if(S[i] != S[1]) fl = 0;
if(fl) putans(1);
for(int i=1; i<=h+1; i++) A[i] = (S[i] == S[i+h]), B[i] = (S[i] == S[i+h+1]);
LA[0] = LB[0] = RA[h+2] = RB[h+1] = 1;
for(int i=1; i<=h+1; i++) LA[i] = LA[i-1] & A[i], LB[i] = LB[i-1] & B[i];
for(int i=h+1; i>=1; i--) RA[i] = RA[i+1] & A[i], RB[i-1] = RB[i] & B[i-1];
int c = 0;
vector<int> p;
for(int i=1; i<=h+1; i++) {
if(LB[i-1] && RA[i+1] && i<=h) ++c, p.push_back(i);
if(LA[i-1] && RB[i]) ++c, p.push_back(i + h);
}
sort(p.begin(), p.end());
if(c >= 2 && p[0] == 1 && p.back() == N) puts("NOT UNIQUE");
else if(c == 0) puts("NOT POSSIBLE");
else putans(p[0]);
return 0;
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:31:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %s", &N, S+1);
~~~~~^~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
384 KB |
Output is correct |
| 2 |
Correct |
2 ms |
384 KB |
Output is correct |
| 3 |
Correct |
3 ms |
512 KB |
Output is correct |
| 4 |
Correct |
2 ms |
384 KB |
Output is correct |
| 5 |
Correct |
10 ms |
356 KB |
Output is correct |
| 6 |
Correct |
2 ms |
384 KB |
Output is correct |
| 7 |
Correct |
2 ms |
384 KB |
Output is correct |
| 8 |
Correct |
2 ms |
384 KB |
Output is correct |
| 9 |
Correct |
2 ms |
384 KB |
Output is correct |
| 10 |
Correct |
2 ms |
384 KB |
Output is correct |
| 11 |
Correct |
2 ms |
384 KB |
Output is correct |
| 12 |
Correct |
2 ms |
384 KB |
Output is correct |
| 13 |
Correct |
2 ms |
384 KB |
Output is correct |
| 14 |
Correct |
2 ms |
384 KB |
Output is correct |
| 15 |
Correct |
2 ms |
384 KB |
Output is correct |
| 16 |
Correct |
2 ms |
384 KB |
Output is correct |
| 17 |
Correct |
2 ms |
384 KB |
Output is correct |
| 18 |
Correct |
2 ms |
384 KB |
Output is correct |
| 19 |
Correct |
2 ms |
384 KB |
Output is correct |
| 20 |
Correct |
2 ms |
384 KB |
Output is correct |
| 21 |
Correct |
2 ms |
384 KB |
Output is correct |
| 22 |
Correct |
2 ms |
384 KB |
Output is correct |
| 23 |
Correct |
2 ms |
384 KB |
Output is correct |
| 24 |
Correct |
2 ms |
384 KB |
Output is correct |
| 25 |
Correct |
2 ms |
256 KB |
Output is correct |
| 26 |
Correct |
2 ms |
384 KB |
Output is correct |
| 27 |
Correct |
2 ms |
384 KB |
Output is correct |
| 28 |
Correct |
16 ms |
384 KB |
Output is correct |
| 29 |
Correct |
2 ms |
384 KB |
Output is correct |
| 30 |
Correct |
2 ms |
384 KB |
Output is correct |
| 31 |
Correct |
2 ms |
384 KB |
Output is correct |
| 32 |
Correct |
2 ms |
384 KB |
Output is correct |
| 33 |
Correct |
2 ms |
384 KB |
Output is correct |
| 34 |
Correct |
2 ms |
384 KB |
Output is correct |
| 35 |
Correct |
2 ms |
384 KB |
Output is correct |
| 36 |
Correct |
2 ms |
384 KB |
Output is correct |
| 37 |
Correct |
2 ms |
384 KB |
Output is correct |
| 38 |
Correct |
2 ms |
384 KB |
Output is correct |
| 39 |
Correct |
2 ms |
384 KB |
Output is correct |
| 40 |
Correct |
2 ms |
384 KB |
Output is correct |
| 41 |
Correct |
2 ms |
356 KB |
Output is correct |
| 42 |
Correct |
2 ms |
384 KB |
Output is correct |
| 43 |
Correct |
2 ms |
384 KB |
Output is correct |
| 44 |
Correct |
2 ms |
384 KB |
Output is correct |
| 45 |
Correct |
2 ms |
384 KB |
Output is correct |
| 46 |
Correct |
2 ms |
384 KB |
Output is correct |
| 47 |
Correct |
2 ms |
384 KB |
Output is correct |
| 48 |
Correct |
2 ms |
384 KB |
Output is correct |
| 49 |
Correct |
2 ms |
384 KB |
Output is correct |
| 50 |
Correct |
2 ms |
384 KB |
Output is correct |
| 51 |
Correct |
2 ms |
384 KB |
Output is correct |
| 52 |
Correct |
2 ms |
384 KB |
Output is correct |
| 53 |
Correct |
2 ms |
384 KB |
Output is correct |
| 54 |
Correct |
2 ms |
384 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
62 ms |
11080 KB |
Output is correct |
| 2 |
Correct |
80 ms |
11048 KB |
Output is correct |
| 3 |
Correct |
62 ms |
11128 KB |
Output is correct |
| 4 |
Correct |
62 ms |
11088 KB |
Output is correct |
| 5 |
Correct |
60 ms |
11000 KB |
Output is correct |
| 6 |
Correct |
10 ms |
4224 KB |
Output is correct |
| 7 |
Correct |
51 ms |
5240 KB |
Output is correct |
| 8 |
Correct |
22 ms |
9216 KB |
Output is correct |
| 9 |
Correct |
58 ms |
10008 KB |
Output is correct |
| 10 |
Correct |
57 ms |
9976 KB |
Output is correct |
| 11 |
Correct |
20 ms |
8448 KB |
Output is correct |
| 12 |
Correct |
2 ms |
384 KB |
Output is correct |
| 13 |
Correct |
2 ms |
384 KB |
Output is correct |
| 14 |
Correct |
2 ms |
384 KB |
Output is correct |
| 15 |
Correct |
2 ms |
384 KB |
Output is correct |
| 16 |
Correct |
2 ms |
384 KB |
Output is correct |
| 17 |
Correct |
2 ms |
384 KB |
Output is correct |
| 18 |
Correct |
2 ms |
384 KB |
Output is correct |
| 19 |
Correct |
2 ms |
384 KB |
Output is correct |
| 20 |
Correct |
2 ms |
384 KB |
Output is correct |
| 21 |
Correct |
2 ms |
384 KB |
Output is correct |
| 22 |
Correct |
2 ms |
384 KB |
Output is correct |
| 23 |
Correct |
2 ms |
384 KB |
Output is correct |
| 24 |
Correct |
2 ms |
384 KB |
Output is correct |
| 25 |
Correct |
2 ms |
384 KB |
Output is correct |
| 26 |
Correct |
2 ms |
384 KB |
Output is correct |
| 27 |
Correct |
2 ms |
384 KB |
Output is correct |
| 28 |
Correct |
2 ms |
384 KB |
Output is correct |
| 29 |
Correct |
2 ms |
384 KB |
Output is correct |
| 30 |
Correct |
2 ms |
384 KB |
Output is correct |
| 31 |
Correct |
2 ms |
384 KB |
Output is correct |
| 32 |
Correct |
2 ms |
384 KB |
Output is correct |
| 33 |
Correct |
2 ms |
384 KB |
Output is correct |
| 34 |
Correct |
2 ms |
384 KB |
Output is correct |
| 35 |
Correct |
2 ms |
384 KB |
Output is correct |
| 36 |
Correct |
2 ms |
384 KB |
Output is correct |
| 37 |
Correct |
2 ms |
256 KB |
Output is correct |
| 38 |
Correct |
2 ms |
384 KB |
Output is correct |
| 39 |
Correct |
2 ms |
384 KB |
Output is correct |
| 40 |
Correct |
2 ms |
384 KB |
Output is correct |
| 41 |
Correct |
2 ms |
384 KB |
Output is correct |
| 42 |
Correct |
1 ms |
384 KB |
Output is correct |
| 43 |
Correct |
2 ms |
384 KB |
Output is correct |
| 44 |
Correct |
2 ms |
384 KB |
Output is correct |
| 45 |
Correct |
2 ms |
384 KB |
Output is correct |
| 46 |
Correct |
2 ms |
384 KB |
Output is correct |
| 47 |
Correct |
2 ms |
384 KB |
Output is correct |
| 48 |
Correct |
2 ms |
384 KB |
Output is correct |
| 49 |
Correct |
3 ms |
384 KB |
Output is correct |
| 50 |
Correct |
2 ms |
384 KB |
Output is correct |
| 51 |
Correct |
2 ms |
384 KB |
Output is correct |
| 52 |
Correct |
2 ms |
384 KB |
Output is correct |
| 53 |
Correct |
2 ms |
384 KB |
Output is correct |
| 54 |
Correct |
2 ms |
384 KB |
Output is correct |
