Solution of 11192 - Group Reverse

Problem Description
source:https://uva.onlinejudge.org/external/111/11192.html

Group reversing a string means reversing a string by groups. For example consider a string:   
    “TOBENUMBERONEWEMEETAGAINANDAGAINUNDERBLUEICPCSKY” This string has length 48. We have divided into 8 groups of equal length and so the length of each group is 6. Now we can reverse each of these eight groups to get a new string: 

“UNEBOTNOREBMEEMEWENIAGATAGADNAEDNUNIIEULBRYKSCPC” Given the string and number of groups in it, your program will have to group reverse it. 

Input 

The input file contains at most 101 lines of inputs. Each line contains at integer G (G < 10) which denotes the number of groups followed by a string whose length is a multiple of G. The length of the string is not greater than 100. The string contains only alpha numerals. Input is terminated by a line containing a single zero. 

Output 

For each line of input produce one line of output which contains the group reversed string. 

Sample Input 

3 ABCEHSHSH
5 FA0ETASINAHGRI0NATWON0QA0NARI0
0

Sample Output 

CBASHEHSH 
ATE0AFGHANISTAN0IRAQ0NOW0IRAN0

Solution:

#include <algorithm>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <deque>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#include<stdio.h>
#include<stdlib.h>

using namespace std;

int main()
{
    int n, i,length,glen;
    string source;
    string group;
    while(scanf("%d",&n)==1 && n!=0)
    {
        cin>>source;
        length=source.length();
        glen=length/n;
        for(i=0;i<length;i+=glen)
        {
            group.assign(source,i,glen);
            string::reverse_iterator rit;
            for ( rit=group.rbegin() ; rit < group.rend(); rit++ )
            cout << *rit;
        }

        cout << endl;
    }
    return 0;
}