先除后乘—-先乘后除 不一样 4 / 5 * 2 2 * 4 / 5 三边判断三角形 a + b > c && b + c > a && a + c > b 四舍五入 (int) (a + 0.5); #define ROUND(a) ((int)((a)+0.5)) a = 1.4; printf(“%d
“,(int)a + 0.5); 输出为0 —>>>>(int)a + 0.5 = 1.50000 —->>>>浮点型变为整型 为 0

printf   

http://blog.sina.com.cn/s/blog_4b9eab320100mvmp.html

http://stackoverflow.com/questions/7480097/what-happens-to-a-float-variable-when-d-is-used-in-a-printf

http://www.cnblogs.com/xiao_bird/archive/2010/03/26/1696908.html

http://blog.csdn.net/yahohi/article/details/7701434

typedef

http://www.cnblogs.com/SweetDream/archive/2006/05/10/395921.html    定义函数指针？？？？

http://www.kuqin.com/language/20090322/41866.html

字符串字面值、C风格字符串、C++风格字符串

http://www.cnblogs.com/coveted/archive/2011/12/28/2304509.html