#include <iostream>
#include <stdio.h>
#include <vector>
#include <string>
#include <map>
const int N = 2000010;
const int rem = 1e9 + 7;
using namespace std;
int n;
char st[N];
int hsh[N], deg_27[N];
vector <int> ans;
map <int,int> mp;
int get_hesh(int l, int r) {
if (l > r) return 0;
int ans = ((long long)hsh[r] - (long long)hsh[l - 1] * deg_27[r - l + 1]) % rem;
return (ans + rem) % rem;
}
int main() {
scanf("%d %s", &n, st);
if (!(n & 1)) {
printf("NOT POSSIBLE\n");
return 0;
}
deg_27[0] = 1;
for (int i = 0; i < n; i++) {
hsh[i + 1] = ((long long)hsh[i] * 27 + st[i] - 'A' + 1) % rem;
deg_27[i + 1] = ((long long)deg_27[i] * 27) % rem;
}
int a_len = (n - 1) >> 1;
for (int i = 1; i <= n; i++) {
int whole_hesh_left, whole_hesh_right;
if (i <= a_len) {
int remaining = a_len - i + 1;
int hsh_right = get_hesh(i + 1, i + remaining);
int hsh_left = hsh[i - 1];
whole_hesh_left = ((long long)hsh_left * deg_27[remaining] + hsh_right) % rem;
} else {
whole_hesh_left = hsh[a_len];
}
int l_0 = n - a_len + 1;
if (i >= l_0) {
l_0--;
int remaining = n - i;
int hsh_right = get_hesh(i + 1, n);
int hsh_left = get_hesh(l_0, i - 1);
whole_hesh_right = ((long long)hsh_left * deg_27[remaining] + hsh_right) % rem;
} else {
whole_hesh_right = get_hesh(l_0, n);
}
if (whole_hesh_left == whole_hesh_right && mp[whole_hesh_left] == 0) {
mp[whole_hesh_left] = 1;
ans.push_back(i - 1);
}
// printf("%d %d \n", whole_hesh_left, whole_hesh_right);
}
if (ans.size() > 1) {
printf("NOT UNIQUE\n");
} else if (ans.size() == 0) {
printf("NOT POSSIBLE\n");
} else {
int arr = ans[0];
string res = st;
res.erase(res.begin() + arr);
cout << res.substr(0, a_len) << "\n";
}
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:25:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %s", &n, st);
^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
19596 KB |
Output is correct |
2 |
Correct |
0 ms |
19596 KB |
Output is correct |
3 |
Correct |
0 ms |
19596 KB |
Output is correct |
4 |
Correct |
0 ms |
19596 KB |
Output is correct |
5 |
Correct |
0 ms |
19596 KB |
Output is correct |
6 |
Correct |
0 ms |
19596 KB |
Output is correct |
7 |
Correct |
0 ms |
19596 KB |
Output is correct |
8 |
Correct |
0 ms |
19596 KB |
Output is correct |
9 |
Correct |
0 ms |
19596 KB |
Output is correct |
10 |
Correct |
0 ms |
19596 KB |
Output is correct |
11 |
Correct |
0 ms |
19596 KB |
Output is correct |
12 |
Correct |
0 ms |
19596 KB |
Output is correct |
13 |
Correct |
0 ms |
19596 KB |
Output is correct |
14 |
Correct |
0 ms |
19596 KB |
Output is correct |
15 |
Correct |
0 ms |
19596 KB |
Output is correct |
16 |
Correct |
0 ms |
19596 KB |
Output is correct |
17 |
Correct |
0 ms |
19596 KB |
Output is correct |
18 |
Correct |
0 ms |
19596 KB |
Output is correct |
19 |
Correct |
0 ms |
19596 KB |
Output is correct |
20 |
Correct |
0 ms |
19596 KB |
Output is correct |
21 |
Correct |
0 ms |
19596 KB |
Output is correct |
22 |
Correct |
0 ms |
19596 KB |
Output is correct |
23 |
Correct |
0 ms |
19596 KB |
Output is correct |
24 |
Correct |
0 ms |
19596 KB |
Output is correct |
25 |
Correct |
0 ms |
19596 KB |
Output is correct |
26 |
Correct |
0 ms |
19596 KB |
Output is correct |
27 |
Correct |
0 ms |
19596 KB |
Output is correct |
28 |
Correct |
0 ms |
19596 KB |
Output is correct |
29 |
Correct |
0 ms |
19596 KB |
Output is correct |
30 |
Correct |
0 ms |
19596 KB |
Output is correct |
31 |
Correct |
0 ms |
19596 KB |
Output is correct |
32 |
Correct |
0 ms |
19596 KB |
Output is correct |
33 |
Correct |
0 ms |
19596 KB |
Output is correct |
34 |
Correct |
0 ms |
19596 KB |
Output is correct |
35 |
Correct |
0 ms |
19596 KB |
Output is correct |
36 |
Correct |
0 ms |
19596 KB |
Output is correct |
37 |
Correct |
0 ms |
19596 KB |
Output is correct |
38 |
Correct |
0 ms |
19596 KB |
Output is correct |
39 |
Correct |
0 ms |
19596 KB |
Output is correct |
40 |
Correct |
0 ms |
19596 KB |
Output is correct |
41 |
Correct |
0 ms |
19596 KB |
Output is correct |
42 |
Correct |
0 ms |
19596 KB |
Output is correct |
43 |
Correct |
0 ms |
19596 KB |
Output is correct |
44 |
Correct |
0 ms |
19596 KB |
Output is correct |
45 |
Correct |
0 ms |
19596 KB |
Output is correct |
46 |
Correct |
0 ms |
19596 KB |
Output is correct |
47 |
Correct |
0 ms |
19596 KB |
Output is correct |
48 |
Correct |
0 ms |
19596 KB |
Output is correct |
49 |
Correct |
0 ms |
19596 KB |
Output is correct |
50 |
Correct |
0 ms |
19596 KB |
Output is correct |
51 |
Correct |
0 ms |
19596 KB |
Output is correct |
52 |
Correct |
0 ms |
19596 KB |
Output is correct |
53 |
Correct |
0 ms |
19596 KB |
Output is correct |
54 |
Correct |
0 ms |
19596 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
73 ms |
22532 KB |
Output is correct |
2 |
Correct |
93 ms |
22532 KB |
Output is correct |
3 |
Correct |
76 ms |
22532 KB |
Output is correct |
4 |
Correct |
73 ms |
22532 KB |
Output is correct |
5 |
Correct |
59 ms |
22532 KB |
Output is correct |
6 |
Correct |
3 ms |
19596 KB |
Output is correct |
7 |
Correct |
66 ms |
22532 KB |
Output is correct |
8 |
Correct |
66 ms |
19596 KB |
Output is correct |
9 |
Correct |
56 ms |
22236 KB |
Output is correct |
10 |
Correct |
53 ms |
22236 KB |
Output is correct |
11 |
Correct |
53 ms |
19596 KB |
Output is correct |
12 |
Correct |
0 ms |
19596 KB |
Output is correct |
13 |
Correct |
0 ms |
19596 KB |
Output is correct |
14 |
Correct |
0 ms |
19596 KB |
Output is correct |
15 |
Correct |
0 ms |
19596 KB |
Output is correct |
16 |
Correct |
0 ms |
19596 KB |
Output is correct |
17 |
Correct |
0 ms |
19596 KB |
Output is correct |
18 |
Correct |
0 ms |
19596 KB |
Output is correct |
19 |
Correct |
0 ms |
19596 KB |
Output is correct |
20 |
Correct |
0 ms |
19596 KB |
Output is correct |
21 |
Correct |
0 ms |
19596 KB |
Output is correct |
22 |
Correct |
0 ms |
19596 KB |
Output is correct |
23 |
Correct |
0 ms |
19596 KB |
Output is correct |
24 |
Correct |
0 ms |
19596 KB |
Output is correct |
25 |
Correct |
0 ms |
19596 KB |
Output is correct |
26 |
Correct |
0 ms |
19596 KB |
Output is correct |
27 |
Correct |
0 ms |
19596 KB |
Output is correct |
28 |
Correct |
0 ms |
19596 KB |
Output is correct |
29 |
Correct |
0 ms |
19596 KB |
Output is correct |
30 |
Correct |
0 ms |
19596 KB |
Output is correct |
31 |
Correct |
0 ms |
19596 KB |
Output is correct |
32 |
Correct |
0 ms |
19596 KB |
Output is correct |
33 |
Correct |
0 ms |
19596 KB |
Output is correct |
34 |
Correct |
0 ms |
19596 KB |
Output is correct |
35 |
Correct |
0 ms |
19596 KB |
Output is correct |
36 |
Correct |
0 ms |
19596 KB |
Output is correct |
37 |
Correct |
0 ms |
19596 KB |
Output is correct |
38 |
Correct |
0 ms |
19596 KB |
Output is correct |
39 |
Correct |
0 ms |
19596 KB |
Output is correct |
40 |
Correct |
0 ms |
19596 KB |
Output is correct |
41 |
Correct |
0 ms |
19596 KB |
Output is correct |
42 |
Correct |
0 ms |
19596 KB |
Output is correct |
43 |
Correct |
0 ms |
19596 KB |
Output is correct |
44 |
Correct |
0 ms |
19596 KB |
Output is correct |
45 |
Correct |
0 ms |
19596 KB |
Output is correct |
46 |
Correct |
0 ms |
19596 KB |
Output is correct |
47 |
Correct |
0 ms |
19596 KB |
Output is correct |
48 |
Correct |
0 ms |
19596 KB |
Output is correct |
49 |
Correct |
0 ms |
19596 KB |
Output is correct |
50 |
Correct |
0 ms |
19596 KB |
Output is correct |
51 |
Correct |
0 ms |
19596 KB |
Output is correct |
52 |
Correct |
0 ms |
19596 KB |
Output is correct |
53 |
Correct |
0 ms |
19596 KB |
Output is correct |
54 |
Correct |
0 ms |
19596 KB |
Output is correct |