#include <iostream>
using namespace std;
int main()
{
int a,b,t,i,max;
while(cin >> a >> b)
{
cout << a << " " << b << " ";
if(a>b)//大小不确定
{
t = a;
a = b;
b = t;
}
max = 0;
for(i = a; i<=b; i++)
{
int n = i, sum = 1;
while(n-1)//等于1时就结束
{
if(n%2)
n = 3*n+1;
else
n = n/2;
sum++;
}
if(sum>max)
max = sum;
}
cout << max << endl;
}
return 0;
}
原文：http://www.cnblogs.com/wangkun1993/p/6284131.html