This very question of God, just learn BSGS, now work the problem solution to a problem and then go to the blogs up.
#include<iostream> #include<cstdio> #include<cmath> #include<map> using namespace std; int T,a,b,k,num,ans,d,dp[10000000]; map<int,int> mp; int qw(int a,int b,int mod) { int ans=1; for(;b;b>>=1,a=1LL*a*a%mod) if(b&1) ans=1LL*ans*a%mod; return ans; } int gcd(int a,int b) { return b==0?a:gcd(b,a%b); } int BSGS(int y,int z,int p) { int n=sqrt(p)+1; z%=p; if(y==0) return z==0?0:-1; mp.clear(); for(int i=0,t=z;i<n;i++,t=1LL*t*y%p) mp[t]=i; int fac=qw(y,n,p); for(int i=0,t=1;i<=n;i++,t=1LL*t*fac%p) { int rank=mp.find(t)==mp.end()?-1:mp[t]; if(rank>=0&&i*n-rank>=0) return i*n-rank; } return -1; } int primeroot(int p,int phi) { d=0; for(int i=2;1LL*i*i<=phi;i++) if(phi%i==0) dp[++d]=i,dp[++d]=phi/i; for(int i=2;;i++) { int j; for(j=1;j<=d;j++) if(qw(i,dp[j],p)==1) break; if(j==d+1) return i; } return 0; } int solit(int a,int b,int p,int k,int pk) { int phi=pk-pk/p; int g=primeroot(pk,phi); int indB=BSGS(g,b,pk); int ans=gcd(phi,a); if(indB%ans!=0) return 0; return ans; } int stcit(int a,int b,int p,int k,int pk) { if(b%pk==0) return qw(p,k-(k-1)/a-1,2100000000); b=b%pk; if(gcd(pk,b)>1) { int GCD=gcd(b,pk),cnt=0; while(GCD%p==0) GCD/=p,b/=p,pk/=p,cnt++; if(a%cnt!=0) return 0; return qw(p,-cnt/a+cnt,2100000000)*solit(a,b,p,k,pk); } return solit(a,b,p,k,pk); } void work(int a,int b,int k) { for(int i=2;1LL*i*i<=k;i++) if(k%i==0) { int p=i,pk=1,num=0; for(;k%p==0;k/=p,pk*=p,num++); ans=ans*stcit(a,b,p,num,pk); } if(k>1) ans=ans*stcit(a,b,k,1,k); } int main() { scanf("%d",&T); while(T--) { scanf("%d%d%d",&a,&b,&k); k=k<<1|1;ans=1; work(a,b,k); printf("%d\n",ans); } }