#include<bits/stdc++.h>
using namespace std;
#define N 2000005
long long hx[N],po[N],p=31,cnt,ans,l,r,mod=1e9+7;
char s[N];
map<long long,int> mp;
int main(){
int n,i,mid;
scanf("%d %s",&n,s+1);
po[0]=1;
for(i=1;i<=n;i++)po[i]=po[i-1]*p%mod;
for(i=1;i<=n;i++)hx[i]=(hx[i-1]*p+s[i]-'A'+1)%mod;
mid=(n+1)/2;
if(hx[mid-1]==(hx[n]-hx[mid]*po[n-mid]%mod+mod)%mod)mp[hx[mid-1]],ans=mid;
if((hx[mid]-hx[1]*po[mid-1]%mod+mod)%mod==(hx[n]-hx[mid]*po[n-mid]%mod+mod)%mod)mp[(hx[mid]-hx[1]*po[mid-1]%mod+mod)%mod],ans=1;
if(hx[mid-1]==(hx[n-1]-hx[mid-1]*po[n-mid]%mod+mod)%mod)mp[hx[mid-1]],ans=n;
for(i=2;i<mid;i++){
l=(hx[i-1]*po[mid-i]%mod+hx[mid]-hx[i]*po[mid-i]%mod+mod)%mod;
r=(hx[n]-hx[mid]*po[n-mid]%mod+mod)%mod;
if(l==r)mp[l],ans=i;
}
for(i=mid+1;i<n;i++){
l=hx[mid-1];
r=((hx[i-1]-hx[mid-1]*po[i-mid]%mod+mod)%mod*po[n-i]%mod+(hx[n]-hx[i]*po[n-i]%mod+mod)%mod)%mod;
if(l==r)mp[l],ans=i;
}
if(mp.size()==0)printf("NOT POSSIBLE");
else if(mp.size()>1)printf("NOT UNIQUE");
else{
for(i=1,cnt=0;cnt<mid-1;i++)if(i!=ans)printf("%c",s[i]),cnt++;
}
return 0;
}
Compilation message
friends.cpp: In function 'int main()':
friends.cpp:11:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
11 | scanf("%d %s",&n,s+1);
| ~~~~~^~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
212 KB |
Output is correct |
| 4 |
Correct |
0 ms |
212 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
212 KB |
Output is correct |
| 7 |
Correct |
1 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
212 KB |
Output is correct |
| 10 |
Correct |
1 ms |
340 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
212 KB |
Output is correct |
| 14 |
Correct |
1 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
212 KB |
Output is correct |
| 19 |
Correct |
0 ms |
212 KB |
Output is correct |
| 20 |
Correct |
0 ms |
212 KB |
Output is correct |
| 21 |
Correct |
1 ms |
212 KB |
Output is correct |
| 22 |
Correct |
1 ms |
212 KB |
Output is correct |
| 23 |
Correct |
0 ms |
212 KB |
Output is correct |
| 24 |
Correct |
0 ms |
212 KB |
Output is correct |
| 25 |
Correct |
0 ms |
212 KB |
Output is correct |
| 26 |
Correct |
0 ms |
212 KB |
Output is correct |
| 27 |
Correct |
0 ms |
212 KB |
Output is correct |
| 28 |
Correct |
0 ms |
212 KB |
Output is correct |
| 29 |
Correct |
0 ms |
212 KB |
Output is correct |
| 30 |
Correct |
0 ms |
212 KB |
Output is correct |
| 31 |
Correct |
0 ms |
212 KB |
Output is correct |
| 32 |
Correct |
0 ms |
212 KB |
Output is correct |
| 33 |
Correct |
0 ms |
212 KB |
Output is correct |
| 34 |
Correct |
0 ms |
212 KB |
Output is correct |
| 35 |
Correct |
1 ms |
212 KB |
Output is correct |
| 36 |
Correct |
0 ms |
212 KB |
Output is correct |
| 37 |
Correct |
0 ms |
212 KB |
Output is correct |
| 38 |
Correct |
0 ms |
212 KB |
Output is correct |
| 39 |
Correct |
0 ms |
212 KB |
Output is correct |
| 40 |
Correct |
0 ms |
212 KB |
Output is correct |
| 41 |
Correct |
1 ms |
212 KB |
Output is correct |
| 42 |
Correct |
0 ms |
212 KB |
Output is correct |
| 43 |
Correct |
0 ms |
212 KB |
Output is correct |
| 44 |
Correct |
1 ms |
340 KB |
Output is correct |
| 45 |
Correct |
1 ms |
340 KB |
Output is correct |
| 46 |
Correct |
1 ms |
340 KB |
Output is correct |
| 47 |
Correct |
1 ms |
340 KB |
Output is correct |
| 48 |
Correct |
1 ms |
340 KB |
Output is correct |
| 49 |
Correct |
1 ms |
340 KB |
Output is correct |
| 50 |
Correct |
1 ms |
340 KB |
Output is correct |
| 51 |
Correct |
1 ms |
340 KB |
Output is correct |
| 52 |
Correct |
1 ms |
308 KB |
Output is correct |
| 53 |
Correct |
1 ms |
340 KB |
Output is correct |
| 54 |
Correct |
1 ms |
312 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
172 ms |
34612 KB |
Output is correct |
| 2 |
Correct |
164 ms |
34464 KB |
Output is correct |
| 3 |
Correct |
171 ms |
34444 KB |
Output is correct |
| 4 |
Correct |
169 ms |
34440 KB |
Output is correct |
| 5 |
Correct |
168 ms |
34440 KB |
Output is correct |
| 6 |
Correct |
134 ms |
35468 KB |
Output is correct |
| 7 |
Correct |
173 ms |
36496 KB |
Output is correct |
| 8 |
Correct |
115 ms |
32012 KB |
Output is correct |
| 9 |
Correct |
157 ms |
32912 KB |
Output is correct |
| 10 |
Correct |
151 ms |
32836 KB |
Output is correct |
| 11 |
Correct |
106 ms |
29644 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
1 ms |
212 KB |
Output is correct |
| 14 |
Correct |
1 ms |
212 KB |
Output is correct |
| 15 |
Correct |
1 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
212 KB |
Output is correct |
| 19 |
Correct |
0 ms |
212 KB |
Output is correct |
| 20 |
Correct |
0 ms |
212 KB |
Output is correct |
| 21 |
Correct |
0 ms |
212 KB |
Output is correct |
| 22 |
Correct |
1 ms |
212 KB |
Output is correct |
| 23 |
Correct |
0 ms |
212 KB |
Output is correct |
| 24 |
Correct |
1 ms |
212 KB |
Output is correct |
| 25 |
Correct |
1 ms |
212 KB |
Output is correct |
| 26 |
Correct |
0 ms |
212 KB |
Output is correct |
| 27 |
Correct |
1 ms |
212 KB |
Output is correct |
| 28 |
Correct |
1 ms |
212 KB |
Output is correct |
| 29 |
Correct |
1 ms |
212 KB |
Output is correct |
| 30 |
Correct |
0 ms |
212 KB |
Output is correct |
| 31 |
Correct |
1 ms |
212 KB |
Output is correct |
| 32 |
Correct |
1 ms |
212 KB |
Output is correct |
| 33 |
Correct |
1 ms |
212 KB |
Output is correct |
| 34 |
Correct |
1 ms |
212 KB |
Output is correct |
| 35 |
Correct |
0 ms |
212 KB |
Output is correct |
| 36 |
Correct |
0 ms |
212 KB |
Output is correct |
| 37 |
Correct |
0 ms |
212 KB |
Output is correct |
| 38 |
Correct |
1 ms |
212 KB |
Output is correct |
| 39 |
Correct |
1 ms |
212 KB |
Output is correct |
| 40 |
Correct |
1 ms |
312 KB |
Output is correct |
| 41 |
Correct |
1 ms |
212 KB |
Output is correct |
| 42 |
Correct |
1 ms |
212 KB |
Output is correct |
| 43 |
Correct |
0 ms |
212 KB |
Output is correct |
| 44 |
Correct |
0 ms |
312 KB |
Output is correct |
| 45 |
Correct |
0 ms |
212 KB |
Output is correct |
| 46 |
Correct |
0 ms |
308 KB |
Output is correct |
| 47 |
Correct |
1 ms |
312 KB |
Output is correct |
| 48 |
Correct |
0 ms |
212 KB |
Output is correct |
| 49 |
Correct |
1 ms |
340 KB |
Output is correct |
| 50 |
Correct |
1 ms |
212 KB |
Output is correct |
| 51 |
Correct |
1 ms |
328 KB |
Output is correct |
| 52 |
Correct |
0 ms |
212 KB |
Output is correct |
| 53 |
Correct |
0 ms |
212 KB |
Output is correct |
| 54 |
Correct |
0 ms |
212 KB |
Output is correct |
