标签：EDA int ber limit using 正整数 names board and
8
11
16
0
Case 1: 1 Case 2: 2 Case 3: 0
由x个n组成的数可以写成n(10^x-1)/9
#include<cstdio> #include<cstring> #include<algorithm> using namespace std; typedef long long ll; ll gcd(ll a,ll b){ return b?gcd(b,a%b):a; } ll getphi(ll n){ ll ans=n; for (ll i=2;i*i<=n;i++){ if(n%i==0){ ans=ans/i*(i-1); while(n%i==0) n/=i; } } if(n>1) ans=ans*(n-1)/n; return ans; } ll quickmod(ll a,ll b,ll p){ ll ans=1%p; for (;b;b>>=1){ if(b&1) ans=ans*a%p; a=a*a%p; } return ans; } int main(){ ll l; ll t=0; while(scanf("%lld",&l)&&l!=0){ ++t; ll ans=999999999999; ll d=gcd(l,8); ll k=9*l/d; ll phi=getphi(k); if(gcd(k*9/gcd(k,8),10)!=1) { printf("Case %lld: 0\n",t); continue; } for (ll i=1;i*i<=phi;i++){ if(phi%i==0){ if(quickmod(10,i,k)==1%k) ans=min(ans,i); else if(quickmod(10,phi/i,k)==1%k) ans=min(ans,phi/i); } } if(ans==999999999999) printf("Case %lld: 0\n",t); else printf("Case %lld: %lld\n",t,ans); } return 0; }
标签：EDA int ber limit using 正整数 names board and
原文地址：https://www.cnblogs.com/lmjer/p/9095583.html
