Cod sursa(job #1060837)

Utilizator auRSTARHreapca Aurelian auRSTAR Data 18 decembrie 2013 20:15:37
Problema Suma divizorilor Scor 60
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.19 kb
#include<cstdio>
#define MOD 9901
#include<bitset>
#include<vector>
using namespace std;
bitset<10010> notprim;
vector<int> V;
int A,B,result,i,exp;

int pow(int x,int y)
{
    int res=1;
    for(;y;y>>=1)
    {
        if(y&1)
            res=(res*x)%MOD;
        x=(x*x)%MOD;
    }
    return res;
}
void precalculeazaPrim()
{
    V.push_back(2);
    int i,j;
    for(i=3;i<=10000;i+=2)
    {
        if(i&1 && !notprim[i])
        {
            V.push_back(i);
            for(j=i*i;j<=10000;j+=i)
                notprim[j]=1;
        }
    }
}
int main()
{
    freopen("sumdiv.in","r",stdin);
    freopen("sumdiv.out","w",stdout);
    precalculeazaPrim();
    scanf("%d%d",&A,&B);
    if(A==1){printf("1\n");return 0;}
    result=1;
    for(vector<int>::iterator it=V.begin();it!=V.end();it++)
    {
        i=*it;
        for(exp=0;!(A%i);exp++,A/=i);
        if(exp)
        {
            result=(result*(pow(i,(exp*B+1))-1))%MOD;
            result=(result*pow(i-1,MOD-2))%MOD;
        }
    }
    if(A>1)
    {
        result=(result*(pow(A,B+1)-1))%MOD;
        result=(result*pow(A-1,MOD-2))%MOD;
    }
    printf("%d\n",result);
    return 0;
}