My solution is 20 lines.
Easy problem.

#pragma comment(linker, "/STACK:16777216")
#include <stdio.h>
#include <string.h>
#define size 20010
char str[size];
char arr[size];
int i=0;
 void recurse(int low,int high){
      int mid;
     if(low>high)
         return;
     mid = (low+high)/2;
     arr[mid] = str[i++];
     recurse(low,mid-1);
     recurse(mid+1,high);
 }

 int main(){
    scanf(" %[^\n]s",str);
    recurse(0,strlen(str)-1);
    printf("%s\n",arr);
 return 0;
 }

/*I simply used recursion and its working for all the test I know presently.Please tell me what is the problem in the code*/

My solution in Python 3 took 0.078 seconds and 516 KB with recursion. Can you do it faster?

Не понимаю фразу:"Строка должна оканчиваться символом перевода строки." Что это интересно за символ в паскале?

Мой код:
const Nmax=21000;
var
 a,s:array[1..Nmax] of char;
 N,i,L,R:longint;
 ch:char;

procedure Solve(L,R,i:longint);
 var m:longint;
begin
 if(R-L>1) then begin
  m:=(L+R) div 2;
  a[m]:=s[i];
  Solve(L,m-1,i+1);
  Solve(m+1,R,m-L+i+1);
 end
 else begin
  a[l]:=s[i];
  if(R>L) then a[R]:=s[i+1];
 end;
end;

begin
 N:=0;
 while not eof do begin
  read(ch);
  inc(N);
  s[n]:=ch;
 end;

 L:=1;
 R:=N;
 Solve(L,R,1);
 for i:=1 to N-1 do write(a[i]);
 writeln(a[n]);
end.

Test 15 is a space or multispace!! Be careful!!

Test : abcdefgh
Answer : dbacfeg
Is this answer correct?

Does anybody has any idea?

Test : abcdefgh
Answer : dbacfeg
Is this answer correct?

What is "г рковоаззи- аул лаывгвдяыеат"?
I have no desire to suffer with Russian letters in the console.

where i am wrong please write me aramvmv@mail.ru
#include <iostream>
using namespace std;
__int64 i,n,k, o[20110]={0},l=0, s,t,j,m,r;    char a[20110], c[20110];
int main()
{
cin.ignore();
cin.getline(a,20110); n=strlen(a); k=n;
t=1; while(k!=0) {c[(k+1)/2]=a[t]; o[(k+1)/2]=1; k=(k+1)/2; t++; }
for(j=0;j<n/4;j++) {
for(i=1;i<=n;i++) if(o[i]==0) {l=1; m=s=i; while(o[i+l]==0)
{l++; m+=i+l;}
if(l==0) break;
if(l==1) {c[s]=a[t]; o[s]=1;} else {k=m/l;
while(k>=s)
{c[k]=a[t]; o[(k+1)/2]=1; l/=2;m=0; for(r=s;r<s+l;r++)m+=r; k=m/l; t++; }}}}
for(i=1;i<=n;i++) cout<<c[i]; return 0;}

My program passes tests "kyaVs alisse uop." and "gtorhoprahy" but get WA1.
Please help.

With array of 20001 chars (with '\0') I got wa17, but of 20002 I got AC. So the input string can contain 20001 chars, can't it? And in the statement has been said "The text is no longer than 20000"...

please smb send me the solution or the idea
my mail is vgvavlad@gmail.com

Mods, send input data for test1 please. Trying to solve the problem second day already. Thx

vanvector@mail.ru

If using Java BufferedReader pay attention on number of symbols read.

While testing in eclipse I used N-1. But on Timus server N-2 was accepted

Edited by author 06.10.2009 16:13

orthography gives gtorhoprahy
but
“one eye, one horn, but not a rhino” gives
“reo ac wpeosr tu fdbmo heinoa  cnrer”
where are the comma's gone??? somebody please help me understand the problem

Edited by author 10.08.2009 12:02

Edited by author 10.08.2009 12:02

Edited by author 10.08.2009 12:02

Why Crash (stack overflow)#8  ????

Help,please =)

Take care of it.