lucas模板

 1 ll PowMod(ll a,ll b,ll MOD){  
 2     ll ret=1;  
 3     while(b){  
 4         if(b&1) ret=(ret*a)%MOD;  
 5         a=(a*a)%MOD;  
 6         b>>=1;  
 7     }  
 8     return ret;  
 9 }  
10 ll fac[110219];  
11 ll Get_Fact(ll p)  
12 {  
13     fac[0]=1;  
14     for(int i=1;i<=p;i++)  
15         fac[i]=(fac[i-1]*i)%p;  
16 }  
17 ll Lucas(ll n,ll m,ll p){  
18     ll ret=1;  
19     while(n&&m){  
20         ll a=n%p,b=m%p;  
21         if(a<b) return 0;  
22         ret=(ret*fac[a]*PowMod(fac[b]*fac[a-b]%p,p-2,p))%p;  
23         n/=p;  
24         m/=p;  
25     }  
26     return ret;  
27 }