C: call by value/reference 複習

http://wp.mlab.tw/?p=176
http://www.quanxue.cn/jc_clanguage/CLang/Clang18.html

常用核心記憶體分配函數

[轉貼]http://welkinchen.pixnet.net/blog/post/44174948-%E5%B8%B8%E7%94%A8%E6%A0%B8%E5%BF%83%E8%A8%98%E6%86%B6%E9%AB%94%E5%88%86%E9%85%8D%E5%87%BD%E6%95%B8

3n+1

#include <stdio.h>                                                                                            
#include <stdlib.h>

#define swap(x,y) (x^=y,y^=x,x^=y)

int main()
{
    unsigned long A, B;
    while(scanf("%ld %ld", &A, &B) == 2)
    {   
        printf("%ld %ld ", A, B); 
        if (A > B) swap(A,B);

        unsigned long max = 0;

        unsigned long i;
        for(i = A; i <= B; i++)
        {   
            unsigned long count, n;
            for(count = 0, n = i;;) 
            {   
                count++;
                if(n == 1) break;
                n = (n%2==1)? 3*n+1 : n >> 1;
            }   
            if(count >= max) max = count;
        }   

        printf("%ld\n", max);
    }
    return 0;
}