#include <iostream>
#include <fstream>
#include <iomanip>
#include <cmath>
#include <cassert>
#include <cstring>
#include <math.h>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
#include <complex>
using u32 = unsigned;
using i32 = int;
using i64 = long long;
using u64 = unsigned long long;
using f64 = double;
using f80 = long double;
using namespace std;
using pt = complex<f80>;
#define ALL(x) begin(x), end(x)
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
#define N 3000005
string u;
int n;
constexpr i64 B = 237, M = 1000000007;
i64 a[N], bp[N], ibp[N];
i64 bpowc(i64 a, i64 b)
{
if (!b) return 1;
i64 r = bpowc(a, b>>1);
if (b&1) return r*r%M*a%M;
return r*r%M;
}
int main()
{
ShinLena;
cin >> n >> u;
u = " " + u;
bp[0] = 1;
for (int i = 1; i <= n + 1; ++i) bp[i] = bp[i-1] * B % M;
i64 IB = bpowc(B, M-2);
for (int i = n; i >= 1; --i) ibp[i] = bp[i+1] * IB % M;
for (int i = 1; i <= n; ++i)
a[i] = (a[i-1] + u[i] * bp[i-1] % M) % M;
set<i64> S;
int at = 0;
for (int i = 1; i <= n; ++i)
{
if (i > n / 2)
{
i64 fst = a[n/2];
i64 lst = (a[i-1] - a[n/2] + M) % M;
lst = (lst + (a[n] - a[i] + M) % M * IB % M) % M;
fst = fst * bp[n/2] % M;
if (fst == lst) at = i, S.insert(lst * ibp[n/2] % M);
}
else
{
i64 fst = (a[i-1] + (a[n/2+1] - a[i] + M) % M * IB % M) % M;
i64 lst = (a[n] - a[n/2+1] + M) % M;
fst = fst * bp[n/2+1] % M;
if (fst == lst) at = i, S.insert(lst * ibp[n/2+1] % M);
}
}
if (S.empty())
{
cout << "NOT POSSIBLE";
}
else if (S.size() > 1)
{
cout << "NOT UNIQUE";
}
else
{
u.erase(u.begin() + at);
cout << u.substr(1, n/2);
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2392 KB |
Output is correct |
2 |
Correct |
1 ms |
2396 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
2396 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Correct |
1 ms |
2396 KB |
Output is correct |
7 |
Correct |
1 ms |
2396 KB |
Output is correct |
8 |
Correct |
1 ms |
2396 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2396 KB |
Output is correct |
11 |
Correct |
1 ms |
2648 KB |
Output is correct |
12 |
Correct |
0 ms |
2396 KB |
Output is correct |
13 |
Correct |
1 ms |
2396 KB |
Output is correct |
14 |
Correct |
1 ms |
2516 KB |
Output is correct |
15 |
Correct |
1 ms |
2396 KB |
Output is correct |
16 |
Correct |
1 ms |
2392 KB |
Output is correct |
17 |
Correct |
1 ms |
2396 KB |
Output is correct |
18 |
Correct |
1 ms |
2396 KB |
Output is correct |
19 |
Correct |
1 ms |
2396 KB |
Output is correct |
20 |
Correct |
1 ms |
2396 KB |
Output is correct |
21 |
Correct |
1 ms |
2396 KB |
Output is correct |
22 |
Correct |
1 ms |
2396 KB |
Output is correct |
23 |
Correct |
1 ms |
2392 KB |
Output is correct |
24 |
Correct |
1 ms |
2396 KB |
Output is correct |
25 |
Correct |
1 ms |
2396 KB |
Output is correct |
26 |
Correct |
1 ms |
2392 KB |
Output is correct |
27 |
Correct |
1 ms |
2396 KB |
Output is correct |
28 |
Correct |
1 ms |
2396 KB |
Output is correct |
29 |
Correct |
1 ms |
2396 KB |
Output is correct |
30 |
Correct |
1 ms |
2508 KB |
Output is correct |
31 |
Correct |
1 ms |
2396 KB |
Output is correct |
32 |
Correct |
1 ms |
2396 KB |
Output is correct |
33 |
Correct |
1 ms |
2396 KB |
Output is correct |
34 |
Correct |
1 ms |
2396 KB |
Output is correct |
35 |
Correct |
1 ms |
2396 KB |
Output is correct |
36 |
Correct |
1 ms |
2396 KB |
Output is correct |
37 |
Correct |
1 ms |
2396 KB |
Output is correct |
38 |
Correct |
1 ms |
2396 KB |
Output is correct |
39 |
Correct |
1 ms |
2396 KB |
Output is correct |
40 |
Correct |
1 ms |
2396 KB |
Output is correct |
41 |
Correct |
1 ms |
2396 KB |
Output is correct |
42 |
Correct |
1 ms |
2396 KB |
Output is correct |
43 |
Correct |
1 ms |
2396 KB |
Output is correct |
44 |
Correct |
1 ms |
2396 KB |
Output is correct |
45 |
Correct |
1 ms |
2396 KB |
Output is correct |
46 |
Correct |
1 ms |
2396 KB |
Output is correct |
47 |
Correct |
1 ms |
2392 KB |
Output is correct |
48 |
Correct |
1 ms |
2396 KB |
Output is correct |
49 |
Correct |
1 ms |
2396 KB |
Output is correct |
50 |
Incorrect |
1 ms |
2396 KB |
Output isn't correct |
51 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
52 ms |
54128 KB |
Output is correct |
2 |
Correct |
51 ms |
54088 KB |
Output is correct |
3 |
Correct |
51 ms |
54092 KB |
Output is correct |
4 |
Correct |
52 ms |
54088 KB |
Output is correct |
5 |
Correct |
51 ms |
54092 KB |
Output is correct |
6 |
Correct |
51 ms |
52316 KB |
Output is correct |
7 |
Incorrect |
62 ms |
52304 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |