Bsgs模板

#include<bits/stdc++.h>
#define int long long 
using namespace std;
const int mod=13331;
struct Hash_Tablet{
    int val,nex,id;
}edge[mod<<2];int first[mod<<2],num;
int a,b,c,ans;
void init(){
    memset(first,0,sizeof(first));
    num=0;
}
void insert(int val,int j){
    int Hval=val%mod;
    edge[++num].val=val;
    edge[num].id=j;
    edge[num].nex=first[Hval];
    first[Hval]=num;
}
int find(int val){
    int Hval=val%mod;
    for(int i=first[Hval];i;i=edge[i].nex)
        if(edge[i].val==val)
            return edge[i].id;
    return -1;
}
int Bsgs(int a,int b,int c){
    init();
    if(b==1) return 0;
    int m=ceil(sqrt(c*1.0));
    int j,p=1,x=1;
    for(int i=0;i<m;i++,p=p*a%c)
        insert(p*b%c,i);
    for(int i=m;i<=c+m;i+=m){
        if((j=find(x=x*p%c))!=-1)
            return i-j;
    }return -1;
}
signed main(){
    while(~scanf("%lld%lld%lld",&c,&a,&b)){
        ans=Bsgs(a%c,b%c,c);
        ans==-1?puts("no solution"):printf("%lld\n",ans);
    }return 0;
}