3N+1数链

Description:

给出一个数n

1. if n=1,then end

2. if n is an odd number, then n = 3*n+1, else n=n/2

3. goto step 1

example n = 22

22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1

the length of the above serial is 16, so is the length of 22

Question is that two integer a,b (a<=b) is given, work out the max length of all integer i (a<=i<=b), and print it

 

Solution:

#include <stdio.h>

 int LinkLen(int x)
{
    int len=1;
    while (x!=1)
    {
        if (x%2)x=3*x+1;
        else x/=2;
        
        len++;
    }
    
    return len;
}

 int main ()
{
    int maxLen=0;
    int a=0,b=0,i=0,len=0;
    
    while (scanf ("%d%d",&a,&b)!=EOF)
    {
        for (i=a; i<=b; i++)
        {
            len = LinkLen(i);
            if (len>maxLen)
                maxLen = len;
        }
        
        printf ("%d\n",maxLen);
        maxLen = 0;        
    }
    
    return 0;
}