spoj3105 MOD - Power Modulo Inverted（exbsgs）

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关于exbsgs是个什么东东可以去看看yyb大佬的博客->这里

 //minamoto
 #include<iostream>
 #include<cstdio>
 #include<cmath>
 #include<map>
 #define ll long long
 #define GG {puts("No Solution");}
 using namespace std;
 #define getc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
 char buf[<<],*p1=buf,*p2=buf;
 inline ll read(){
     #define num ch-'0'
     char ch;bool flag=;ll res;
     while(!isdigit(ch=getc()))
     (ch=='-')&&(flag=true);
     for(res=num;isdigit(ch=getc());res=res*+num);
     (flag)&&(res=-res);
     #undef num
     return res;
 }
 map<ll,ll> mp;
 inline ll gcd(ll a,ll b){
     if(!b) return a;
     while(b^=a^=b^=a%=b);
     return a;
 }
 inline ll ksm(ll a,ll b,ll p){
     ll res=;
     while(b){
         if(b&) (res*=a)%=p;
         (a*=a)%=p,b>>=;
     }
     return res;
 }
 inline void ex_BSGS(ll y,ll z,ll p){
     if(z==) return (void)(puts(""));
     int k=,a=;
     while(true){
         int d=gcd(y,p);if(d==) break;
         if(z%d) return (void)(GG);
         z/=d,p/=d,++k,a=1ll*a*y/d%p;
         if(z==a) return (void)(printf("%d\n",k));
     }
     mp.clear();
     int m=sqrt(p)+;
     for(int i=,t=z;i<m;++i,t=1ll*t*y%p) mp[t]=i;
     for(int i=,tt=ksm(y,m,p),t=1ll*a*tt%p;i<=m;++i,t=1ll*t*tt%p){
         int j=mp.find(t)==mp.end()?-:mp[t];
         if(j>=&&i*m-j+k>=) return (void)(printf("%d\n",i*m-j+k));
     }
     GG;
 }
 int main(){
 //    freopen("testdata.in","r",stdin);
     while(true){
         int x=read(),z=read(),k=read();
         if(x==&&z==&&k==) break;
         ex_BSGS(x,k,z);
     }
     return ;
 }