UVA 371 - Ackermann Functions

/***
Md. Nazmul Hasan
Shahjalal University of Science & Technology,Sylhet.
hasan08sust@gmail.com
***/
#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
#include<map>
#include<vector>
#include<algorithm>
#include<cstring>
#include<sstream>
#include<cmath>
#include <iomanip>
using namespace std ;
typedef long long ll ;
typedef int in ;
typedef unsigned long long ull ;
const double pi = 2*acos(0) ;
#define maxi 40000
#define pf printf
#define sc scanf
#define pb push_back
#define MEM(x,y) (memset((x),(y),sizeof(x)))
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#define MAX(x,y) ((x) > (y) ? (x) : (y))
#define load(array,size)  for(int i=0 ; i<size ; i++) cin>>array[i]  ;
#define new_line  pf("\n")
#define clear_data(array) memset(array,0,sizeof(array))
#define highest_int 2147483647


int main()
{

    ll n,m,mx,mx_num,i,x,cnt;
    while(sc("%lld %lld",&n,&m))
    {
       if(n==0 && m==0)
       break;
       mx =0;
       if(n>m)
      swap(n,m);
       for(i=n ; i<=m ; i++)
       {
         x = i;
         cnt=1;
         if(x%2==0)
         x = x/2;
         else if(x%2!=0)
         x = (3*x)+1;
       
         while(x!=1)
         {
           if(x%2==0)
           {
             x = x/2;
             cnt++;
           }
           else if(x%2!=0)
           {
             x = (3*x)+1;
             cnt++;
           }
         }
        if(mx < cnt)
        {
           mx = cnt;
           mx_num = i;
        }
       }
  cout<<"Between "<<n<<" and "<<m<<", "<<mx_num<<" generates the longest sequence of "<<mx<<" values."<<endl;
    }
    return 0;
}