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Submission #938294

# Submission time Handle Problem Language Result Execution time Memory
938294 2024-03-05T04:20:12 Z UmairAhmadMirza Three Friends (BOI14_friends) C++17
0 / 100
 96 ms 46292 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long
int const N=3e6+5;
int const mod=1e9+9;
int const base=727;
int Hash[N];
int pw[N];
int n;
string s;
void pre(){
  pw[0]=1;
  for(int i=1;i<N;i++)
    pw[i]=(pw[i-1]*base)%mod;
}
void make_Hash(){
  for(int i=1;i<=n;i++)
    Hash[i]=(((Hash[i-1]*base)%mod)+s[i-1])%mod;
}
int compute_Hash(int l,int r){
  return ((Hash[r] - ((Hash[l]*pw[r-l])%mod) )+mod)%mod;
}
int org_Hash1(int e){
  if(e>n/2)
    return Hash[n/2];
  int h=(Hash[e-1]*pw[((n/2)+1)-e])%mod;
  h+=compute_Hash(e,(n/2)+1);
  h%=mod;
  return h;
}
int org_Hash2(int e){
  if(e<=(n/2)+1)
    return compute_Hash((n/2)+1,n);
  int h=(compute_Hash((n/2),e-1)*pw[n-e])%mod;
  h+=compute_Hash(e,n);
  h%=mod;
  return h;
}
string make_str(int p){
  string st="";
  int sz=0;
  int i=0;
  while(i<=n && sz<(n/2)){
    i++;
    if(i==p)
      continue;
    st+=s[i-1];
    sz++;
  }
  return st;
}
signed main() 
{
  cin>>n;
  cin>>s;
  if(n%2==0){
    cout<<"NOT POSSIBLE\n";
    return 0;
  }
  bool b=0;
  for(int i=1;i<n;i++)
    if(s[i]!=s[i-1])
      b=1;
  pre();
  make_Hash();
  int rem=0;
  int cnt=0;
  for(int i=1;i<=n;i++){
    if(org_Hash1(i)==org_Hash2(i)){
      rem=i;
      cnt++;
    }
  }
  if(cnt==0)
    cout<<"NOT POSSIBLE"<<endl;
  else if(cnt>1 && b)
    cout<<"NOT UNIQUE"<<endl;
  else
    cout<<make_str(rem)<<endl;
  return 0;
}

Subtask #1
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 25176 KB Output is correct
2 Correct 16 ms 25180 KB Output is correct
3 Correct 18 ms 25180 KB Output is correct
4 Correct 18 ms 25180 KB Output is correct
5 Correct 16 ms 25176 KB Output is correct
6 Correct 18 ms 25180 KB Output is correct
7 Correct 16 ms 25180 KB Output is correct
8 Correct 16 ms 25196 KB Output is correct
9 Correct 16 ms 25204 KB Output is correct
10 Correct 16 ms 25200 KB Output is correct
11 Correct 17 ms 25180 KB Output is correct
12 Correct 16 ms 25180 KB Output is correct
13 Correct 16 ms 25176 KB Output is correct
14 Correct 17 ms 25216 KB Output is correct
15 Correct 16 ms 25180 KB Output is correct
16 Correct 16 ms 25200 KB Output is correct
17 Correct 16 ms 25180 KB Output is correct
18 Correct 16 ms 25180 KB Output is correct
19 Correct 17 ms 25180 KB Output is correct
20 Correct 16 ms 25176 KB Output is correct
21 Correct 16 ms 25176 KB Output is correct
22 Correct 16 ms 25180 KB Output is correct
23 Correct 16 ms 25176 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 17 ms 25180 KB Output is correct
28 Correct 16 ms 25180 KB Output is correct
29 Correct 16 ms 25180 KB Output is correct
30 Correct 16 ms 25180 KB Output is correct
31 Correct 17 ms 25376 KB Output is correct
32 Correct 16 ms 25180 KB Output is correct
33 Correct 16 ms 25216 KB Output is correct
34 Correct 16 ms 25180 KB Output is correct
35 Correct 16 ms 25180 KB Output is correct
36 Correct 16 ms 25180 KB Output is correct
37 Correct 16 ms 25180 KB Output is correct
38 Correct 16 ms 25212 KB Output is correct
39 Correct 16 ms 25180 KB Output is correct
40 Correct 16 ms 25180 KB Output is correct
41 Correct 16 ms 25176 KB Output is correct
42 Correct 16 ms 25216 KB Output is correct
43 Correct 16 ms 25180 KB Output is correct
44 Correct 16 ms 25180 KB Output is correct
45 Correct 16 ms 25180 KB Output is correct
46 Correct 16 ms 25180 KB Output is correct
47 Correct 16 ms 25212 KB Output is correct
48 Correct 16 ms 25224 KB Output is correct
49 Correct 0 ms 344 KB Output is correct
50 Correct 16 ms 25180 KB Output is correct
51 Correct 16 ms 25180 KB Output is correct
52 Correct 16 ms 25180 KB Output is correct
53 Incorrect 16 ms 25216 KB Output isn't correct
54 Halted 0 ms 0 KB -

Subtask #2
0 / 65.0

# Verdict Execution time Memory Grader output
1 Correct 93 ms 45500 KB Output is correct
2 Correct 96 ms 46292 KB Output is correct
3 Correct 93 ms 45504 KB Output is correct
4 Correct 94 ms 45988 KB Output is correct
5 Incorrect 87 ms 43284 KB Output isn't correct
6 Halted 0 ms 0 KB -