Cod sursă (job #710100)

#include <bits/stdc++.h>

using namespace std;
const int N = 5e5;
char rez[N];
char s[N];
int main()
{
    ifstream in("bart.in");
    ofstream out("bart.out");
    char ch;
    in.get(ch);
    int k = 0;
    rez[k++] = ch;
    int i = 0, j = 0;
    in.get(ch);
    while( ch != '\n'){
      s[i++] = ch;
      if(ch == rez[j % k]){
        j++;
      }
      else{
        for(int ii = k; ii < i + k; ii++){
          rez[ii] = s[ii - k];
        }
        k = k + i;
        j = i = 0;
      }
      in.get(ch);
    }
    for(int ii = 0; ii < k; ii++){
      out << rez[ii];
    }
    return 0;
}