Cod sursă (job #532409)

#include <bits/stdc++.h>

using namespace std;
ifstream in("bart.in");
ofstream out("bart.out");
const int NMAX = 1000003;
char s[NMAX];
int Pi[NMAX];
int i,n,now,r,q,j;
int main() {
    in>>s;
    n=strlen(s);
    for(i=n;i>=1;i--)
        s[i]=s[i-1];
    r=0;
    for(i=2;i<=n;i++) {
        now=Pi[i-1];
        while(now>0&&s[now+1]!=s[i])
            now=Pi[now];
        if(s[now+1]==s[i])
            now++;
        Pi[i]=now;
    }
    r=n-Pi[n];
    for(int i=1;i<=r;i++)
        out<<s[i];
    return 0;
}