2019-04-13 12:37发布 生成海报
#include #include #include #include #include #include #include using namespace std; #define ll long long ll gcd(ll a,ll b) { return b?gcd(b,a%b):a; } ll phi(long long n) { long long rea=n; for(int i=2; i*i<=n; i++) if(n%i==0) { rea=rea-rea/i; do n/=i; while(n%i==0); } if(n>1)rea=rea-rea/n; return rea; } ll exp_mod(ll a,ll b,ll c) { a%=c; ll ans=1; while(b) { if(b&1) ans=ans*a%c; b>>=1,a=a*a%c; } return ans; } int main() { ll a,n; cin>>a>>n; if(gcd(a,n)!=1) { puts("0"); return 0; } ll p=phi(n),l=(ll)sqrt(p*1.0),ans=1e9; for(ll i=1; i<=l; i++) if(p%i==0) { if(exp_mod(a,i,n)==1)ans=min(ans,i); if(exp_mod(a,p/i,n)==1)ans=min(ans,p/i); } printf("%I64d ",ans); return 0; }
{var%20f='http://v.t.sina.com.cn/share/share.php?appkey=1515056452',u=z||d.location,p=['&url=',e(u),'&title=',e(t||d.title),'&source=',e(r),'&sourceUrl=',e(l),'&content=',c||'gb2312','&pic=',e(p||'')].join('');function%20a(){if(!window.open([f,p].join(''),'mb',['toolbar=0,status=0,resizable=1,width=440,height=430,left=',(s.width-440)/2,',top=',(s.height-430)/2].join('')))u.href=[f,p].join('');};if(/Firefox/.test(navigator.userAgent))setTimeout(a,0);else%20a();})(screen,document,encodeURIComponent,'','','https://www.xiaopingtou.cn//data/attach/topic/topicKPo7gB.jpg', '推荐 heljean 的文章《URAL 1456 求a模n的阶》','https://www.xiaopingtou.net/article-51008.html','页面编码gb2312|utf-8默认gb2312'));){kind=link}