BSGS and extended bsgs templates

Bsgs

#include <iostream>//poj2417#include<cstring>#include<cstdio>#include<cmath>#include<algorithm>#definell Long Longusing namespacestd;Const intMaxint= ((1<< -)-1)*2+1;inta,b,c;structhashmap{Static Const intHa=999917, maxe=46340; intE,lnk[ha],son[maxe+5],nxt[maxe+5],w[maxe+5]; intTop,stk[maxe+5]; voidClear () {e=0; while(top) lnk[stk[top--]]=0;} voidADD (intXintY) {son[++e]=y;nxt[e]=lnk[x];w[e]=maxint;lnk[x]=E;} BOOLCountinty) {intx=y%Ha;  for(intj=lnk[x];j;j=Nxt[j])if(Y==son[j])return true; return false; }    int&operator[] (inty) {intx=y%Ha;  for(intj=lnk[x];j;j=Nxt[j])if(Y==son[j])returnW[j]; ADD (x, y); stk[++top]=x;returnW[e]; }}; Hashmap F;intEXGCD (intAintBint&x,int&y) {    if(!B) {x=1; y=0;returnA;} intR=EXGCD (B,a%b,x,y), t=x;x=y;y=t-(A/b) *y; returnR;}intBSGS (intAintBintC) {    if(c==1)if(! Breturna!=1;Else return-1; if(b==1)ifAreturn 0;Else return-1; if(a%c==0)if(! Breturn 1;Else return-1; intM=ceil (sqrt (C)), d=1, base=1; F.clear ();  for(intI=0; i<=m-1; i++)//Save the A^j in a hash table first{F[base]=min (f[base],i); Base= (ll) base*a)%C; }     for(intI=0; i<=m-1; i++)    {        intX,y,r=EXGCD (d,c,x,y); X= (ll) x*b%c+c)%c;//expanding Europe for A^j        if(F.count (x))returnI*M+F[X];//Find the solutionD= (LL) d*base)%C; }    return-1;}intMain () { while(~SCANF ("%d%d%d",&c,&a,&B)) {intans=bsgs (A,B,C); if(ans==-1) printf ("No solution\n"); Elseprintf"%d\n", ans); }    return 0;}

Extended BSGS

#include <iostream>//poj3243#include<cstring>#include<cstdio>#include<cmath>#include<algorithm>#definell Long Longusing namespacestd;Const intMaxint= ((1<< -)-1)*2+1;inta,b,c;structhashmap{Static Const intHa=999917, maxe=46340; intE,lnk[ha],son[maxe+5],nxt[maxe+5],w[maxe+5]; intTop,stk[maxe+5]; voidClear () {e=0; while(top) lnk[stk[top--]]=0;} voidADD (intXintY) {son[++e]=y;nxt[e]=lnk[x];w[e]=maxint;lnk[x]=E;} BOOLCountinty) {intx=y%Ha;  for(intj=lnk[x];j;j=Nxt[j])if(Y==son[j])return true; return false; }    int&operator[] (inty) {intx=y%Ha;  for(intj=lnk[x];j;j=Nxt[j])if(Y==son[j])returnW[j]; ADD (x, y); stk[++top]=x;returnW[e]; }}; Hashmap F;intgcdintAintBB) {    if(!B)returnA; Else returnGCD (b,a%b);}intEXGCD (intAintBint&x,int&y) {    if(!B) {x=1; y=0;returnA;} intR=EXGCD (b,a%b,x,y), t=x; X=y;y=t-(A/b) *y; returnR;}intEXBSGS (intAintBintC) {    if(c==1)if(! Breturna!=1;Else return-1; if(b==1)ifAreturn 0;Else return-1; if(a%c==0)if(! Breturn 1;Else return-1; intR,d=1, num=0;  while((R=GCD (a,c)) >1)    {        if(b%r)return-1; num++; B/=r; C/=r;d= (LL) d*a/r)%C; }     for(intI=0, now=1; i<num;i++,now= (ll) now*a)%C) {if(now==b)returni; }    intM=ceil (sqrt (C)), base=1; F.clear ();  for(intI=0; i<=m-1; i++) {F[base]=min (f[base],i); Base= (ll) base*a)%C; }     for(intI=0; i<=m-1; i++)    {        intX,y,r=EXGCD (d,c,x,y); X= (ll) x*b%c+c)%b; if(F.count (x))returni*m+f[x]+num; D= (ll) d*base)%C; }    return-1;}intMain () { while(~SCANF ("%d%d%d", &a,&c,&b))//a^y MoD c=b    {        if(! a&&! b&&! C Break; intans=exbsgs (A,B,C); if(ans==-1) printf ("No solution\n"); Elseprintf"%d\n", ans); }    return 0;}

BSGS and extended bsgs templates