P2485 [SDOI2011]计算器

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<map>
using namespace std;
typedef long long ll;
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(ch<‘0‘||ch>‘9‘) { if(ch==‘-‘) f=-1; ch=getchar(); }
    while(ch>=‘0‘&&ch<=‘9‘) { x=(x<<1)+(x<<3)+(ch^48); ch=getchar(); }
    return x*f;
}
inline int ksm(int x,int y,int mo)
{
    int res=1;
    while(y)
    {
        if(y&1) res=1ll*res*x%mo;
        x=1ll*x*x%mo; y>>=1;
    }
    return res;
}
int gcd(int a,int b) { return b ? gcd(b,a%b) : a; }
int exgcd(int a,int b,int &x,int &y)
{
    if(!b) { x=1,y=0; return a; }
    int d=exgcd(b,a%b,x,y);
    int t=x; x=y; y=t-a/b*y;
    return d;
}
map <int,int> mp;
void exBSGS(int X,int Z,int mo)
{
    if(Z==1) { printf("0\n"); return; }
    int d=gcd(X,mo),t=0,k=1;
    while(d!=1)
    {
        if(Z%d) { printf("Orz, I cannot find x!\n"); return; }
        t++; Z/=d; mo/=d; k=1ll*k*(X/d)%mo;
        if(k==Z) { printf("%d\n",t); return; }
        d=gcd(X,mo);
    }
    int m=sqrt(mo)+1; mp.clear();
    for(int b=0,s=Z; b<m; b++,s=1ll*s*X%mo) mp[s]=b;
    for(int a=1,p=ksm(X,m,mo),s=1ll*k*p%mo; a<=m+1; a++,s=1ll*s*p%mo)
    {
        if(mp.find(s)==mp.end()) continue;
        printf("%d\n",a*m-mp[s]+t); return;
    }
    printf("Orz, I cannot find x!\n");
}
int T,K;
int main()
{
    T=read(),K=read(); int X,Z,mo;
    while(T--)
    {
        X=read(),Z=read(),mo=read();
        if(K==1) { printf("%d\n",ksm(X,Z,mo)); continue; }
        if(K==3) { exBSGS(X,Z,mo); continue; }
        int A=X,B=mo,x,y,d=exgcd(A,B,x,y);
        if(Z%d) { printf("Orz, I cannot find x!\n"); continue; }
        int t=B/d,ans=(1ll*x*(Z/d)%t+t)%t;
        printf("%d\n",ans);
    }
    return 0;
}