Submission #290249

#	Time	Username	Problem	Language	Result	Execution time	Memory
290249		MasterTaster	Three Friends (BOI14_friends)	C++14	100 / 100	13 ms	5688 KiB

friends

#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define pii pair<int, int>
#define xx first
#define yy second
#define endl "\n"

int n;
string s;

int main()
{
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    cin>>n>>s;

    n=s.size();
    if (n%2==0) { cout<<"NOT POSSIBLE"; exit(0); }

    bool istePolovine=true;
    for (int i=0; i<n/2; i++)
        if (s[i]!=s[n/2+i+1]) istePolovine=false;
    if (istePolovine)
    {
        cout<<s.substr(0, n/2);
        exit(0);
    }

    int koliko1=0; int koliko2=0;
    int j=n/2;
    for (int i=0; i<n/2; i++, j++)
        while (j<n && s[i]!=s[j]) { koliko1++; j++; }

    int k=0;
    for (int i=n/2+1; i<n; i++, k++)
        while (k<=n/2 && s[i]!=s[k]) { /*cout<<i<<" "<<k<<endl;*/ koliko2++; k++; }

    if (koliko1>1 && koliko2>1) cout<<"NOT POSSIBLE";
    else if (koliko1<=1 && koliko2<=1) cout<<"NOT UNIQUE";
    else
    {
        if (koliko1<=1)
            cout<<s.substr(0, n/2);
        else
            cout<<s.substr(n/2+1, n/2);
    }
}

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