Uva 444 - Encoder and Decoder

 /// Header file begin
#include<iostream>
#include<cstdio>
#include<cstring>
#include<map>
#include<string>
#include<vector>
#include<cmath>
#include<cctype>
#include<sstream>
#include<set>
#include<list>
#include<stack>
#include<utility>
#include<queue>
#include<algorithm>
#include<cstdlib>
/// End
//..........
/// Macro
#define sf scanf
#define pf printf
#define lp1(i,n) for(i=0;i<n;i++)
#define lp2(i,n) for(i=1;i<=n;i++)
#define mem(c,v) memset(c,v,sizeof(c))
#define cp(a) cout<<" "<<a<<" "
#define nl puts("")
#define sq(x) ((x)*(x))
#define all(x) x.begin(),x.end()
#define reall(x) x.rbegin(),x.rend()
#define sz size()
#define gc getchar()
#define pb push_back
#define freader freopen("input.txt","r",stdin)
/// End.........

/// Size
#define mx7 20000100
#define mx6 1500000
#define mx5 100005
#define mx4 1000100
#define inf 1<<30                                           //infinity value
#define eps 1e-9
#define mx (65540)
#define mod 1000000007
#define pi acos(-1.0)

/// Macros for Graph

#define white 1
#define gray 2
#define black 3
#define nil 0

using namespace std;
/***************/

/// typedef

typedef long long LL;
typedef long L;
typedef unsigned long long ull;
typedef unsigned long ul;
typedef unsigned int ui;
typedef pair<int, int> pii;
typedef vector<int>vi;
typedef vector<long long> vll;
typedef vector<long>vl;
typedef vector<char>vch;
typedef vector<string>vs;
typedef map<int,int>mpii;
typedef map<int,bool>mpbi;
typedef map<long,bool>mpbl;
typedef map<long long,bool>mpbll;
typedef map<char,int>mpci;
typedef map<char,bool>mpbc;
typedef map<string,int>mpsi;
typedef map<long long,long long>mpll;

/// template

template<class T> T gcd(T a, T b ) {return b<=0?a:gcd(b,a%b);}
template<class T> T large(T a, T b ) {return a>b?a:b;}
template<class T> T small(T a, T b ) {return a<b?a:b;}
template<class T> T diffrnce(T a, T b) {return a-b<0?b-a:a-b;}

void digit_rev(int n)
{
    int a=n;

    while(n>0)
    {
        a=n%10;
        pf("%d",a);
        n/=10;
    }
}

int main()
{
    char ch[1009];

    while(gets(ch))
    {
        int len,i,r;

        if(ch[0]-48>=0 and ch[0]-48<=9)
        {
            len=strlen(ch);
            reverse(ch,ch+len);
            r=0;

            for(i=0;ch[i];i++)
            {
                r=(ch[i]-48)+(r*10);

                if((r>=65 and r<=90) or (r>=97 and r<=122) or (r==32) or (r==33) or (r==44) or 

                      (r==46) or (r==58) or (r==59) or (r==63))
                {
                    pf("%c",r);
                    r=0;
                }

                else
                {
                    continue;
                }
            }
        }

        else
        {
            len=strlen(ch);

            reverse(ch,ch+len);

            for(i=0;i<len;i++)
            {
                digit_rev(ch[i]);
            }
        }

        nl;
    }

    return 0;
}