Cod sursă (job #376962)

#include <fstream>
#include <cstring>
using namespace std;
ifstream in("bart.in");
ofstream out("bart.out");
char ch[500001];
int p[500001];
int main()
{
    int i,j,l,vf=0;
    in.get(ch+1,500001);
    l=strlen(ch+1);
    for(i=2; i<=l; i++)
    {
        while(vf&&ch[i]!=ch[vf+1])
            vf=p[vf];
        if(ch[i]==ch[vf+1])
            vf++;
        p[i]=vf;
    }
    for(i=1;i<=l-p[l];i++)
    {
        out<<ch[i];
    }
    return 0;
}