> 
> A了十分感谢你！！！
> 想再请问一下  为什么while(int(s*100)<int(a*100))会WA的？
> 

The cast to "int" rounds down the figures after the decimal fractions.

ex)
case
s=0.1234
a=0.1235

s < a ===> true

but

int(s*100) < int(a*100) ===> false

because
int(s*100) == 12
int(a*100) == 12