# [**uva-100 The 3n+1 problem**](https://onlinejudge.org/index.php?option=onlinejudge&Itemid=8&page=show_problem&problem=36)
## **Input**
The input will consist of a series of pairs of integers i and j,
one pair of integers per line.
All integers will be less than 10,000 and greater than 0.
You should process all pairs of integers and for each pair determine the maximum cycle length over all integers between and including i and j.
You can assume that no operation overflows a 32-bit integer.
## **Output**
For each pair of input integers i and j you should output i, j,
and the maximum cycle length for integers between and including i and j.
These three numbers should be separated by at least one space with all three numbers on one line and with one line of output for each line of input.
The integers i and j must appear in the output in the same order in which they appeared in the input and should be followed by the maximum cycle length
(on the same line).

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## **Sample input**

1 10
100 200
201 210
900 1000

## **Sample output**

1 10 20
100 200 125
201 210 89
900 1000 174

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## **Solution:**

#include <cstdio>

int main()
{
    int a , b , temp  ;
    while ( scanf("%d%d", &a,&b) != -1  )
    {
        bool change = false ;
        if ( a > b )
        {
            temp = a ;
            a = b ;
            b = temp ;
            change = true ;
        }
        int max = 0 ;
        for ( int i = a ; i <= b ; i ++ )
        {
            int n = i , len = 1 ;
            while (1)
            {
                if ( n == 1 )
                    break ;
                else if ( (n & 1 )  == 0 )
                    ( n >>= 1 )  ;
                else
                    n = n*3 + 1 ;
                len++ ;
            }
            if ( len > max )
                max = len ;
        }
        if ( change  )
        {
            temp = a ;
            a = b ;
            b = temp ;
        }

        printf( "%d %d %d\n", a , b , max ) ;
    }
}

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