http://acm.pku.edu.cn/JudgeOnline/problem?id=1423
n!=(log10(sqrt(4.0*acos(0.0)*n))+n*(log10(n)-log10(exp(1.0)))+1);
n==1 除外
n!=(log10(sqrt(4.0*acos(0.0)*n))+n*(log10(n)-log10(exp(1.0)))+1);
n==1 除外
转载于:https://my.oschina.net/garyun/blog/602856