Cod sursă (job #585151)

#include <iostream>
#include <fstream>
#include <cstring>

#define mac 500001

using namespace std;

ifstream fin("bart.in");
ofstream fout("bart.out");

char s[mac];
int lps[mac];
int mx=0;

int main()
{
    fin.getline(s,mac);
    int n=strlen(s);
    int i=1, ln=0;
    while(i<n)
    {
        if(s[i]==s[ln])
        {
            lps[i]=ln+1;
            ln++;
            i++;
        }
        else
        {
            if(ln!=0) ln=lps[ln-1];
            else
            {
                lps[i]=0;
                i++;
            }
        }
    }
    int nr=lps[n-1];
    mx=n-nr;
    for(int i=0;i<mx;i++)
        fout<<s[i];
    return 0;
}