Submission #956522

#	Time	Username	Problem	Language	Result	Execution time	Memory
956522		ezzzay	Three Friends (BOI14_friends)	C++14	0 / 100	87 ms	5984 KiB

friends

#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define int long long
#define pb push_back
#define ff first
#define ss second
const int N=1e5+5;
vector<int>ans;
 
signed main(){
	int n;
	cin>>n;
	
	string s;
	set<char>st;
	cin>>s;
	for(int i=0;i<n;i++)st.insert(s[i]);
	if(st.size()==1 and n%2){
	    cout<<"NOT UNIQUE";
	    return 0;
	}
	if(n%2==0){
		cout<<"NOT POSSIBLE";
		return 0;
	}
	int l1=0;
	int r1=n/2+1;
	int cnt1=0;
	int u1=0;
	int e1=0;
	while(cnt1!=n/2){
	    if(s[l1]!=s[r1]){
	        l1++;
	        e1=1;
	        u1++;
	        if(u1==2){
	            e1=0;
	            break;
	        }
	    }
	    l1++;
	    r1++;
	    cnt1++;
	}
	int p1=1;
	if(u1==2 and e1==0){
	    p1=0;
	}
	
	reverse(s.begin(),s.end());
	
	int l2=0;
	int r2=n/2+1;
	int cnt2=0;
	int u2=0;
	int e2=0;
	while(cnt2!=n/2){
	    if(s[l2]!=s[r2]){
	        l2++;
	        e2=1;
	        u2++;
	        if(u2==2){
	            e2=0;
	            break;
	        }
	    }
	    l2++;
	    r2++;
	    cnt2++;
	}
	int p2=1;
	if(e1 and e2){
	    cout<<"NOT UNIQUE";
	    return 0;
	}
	
	
	
	
	if(u1==2 and u2==2){
	    cout<<"NOT POSSIBLE";
	    return 0;
	}
	
	
	reverse(s.begin(),s.end());
	if(p1){
	    cout<<s.substr(n/2+1,n/2);
	}
	else{
	    cout<<s.substr(0,n/2);
	}
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:73:6: warning: unused variable 'p2' [-Wunused-variable]
   73 |  int p2=1;
      |      ^~

• Subtask 1: 0 / 35
• Subtask 2: 0 / 65