Divizori--oprimizat

#include <iostream>

using namespace std;
#define NR_E 1000000
#define M_CIUR 40001
#define NR_PRIME 4300
char v[NR_E],ciur[M_CIUR];
int nrp[NR_PRIME];
int main()
{
    int n,k,cnr,poz,d,cnt,max1,i,aux,nr,cnt1,j,n2,rp,cdnr;
    FILE *fin,*fout;
    fin=fopen("divizori.in","r");
    fscanf(fin,"%d%d",&n,&k);
    for(i=2;i<M_CIUR;i++){
        if(ciur[i]==0){
            for(j=i*i;j<M_CIUR;j+=i)
                ciur[j]=1;
        }
    }
    n2=0;
    for(i=2;i<M_CIUR;i++){
        if(ciur[i]==0){
            nrp[n2]=i;
            n2++;
        }
    }
    fgetc(fin);
    for(i=0;i<n;i++)
        v[i]=fgetc(fin)-'0';
    fclose(fin);
    for(i=0;i<=n/2;i++){
        aux=v[n-1-i];
        v[n-1-i]=v[i];
        v[i]=aux;
    }
    cnr=999999999;
    max1=0;
    cnt1=0;
    while((n>1)||(v[0]!=2 && v[0]!=1)){
        nr=0;
        if(n-k>=0){
            for(i=n-1;i>=n-k;i--){
                nr=nr*10+v[i];
                v[i]=0;
            }
        }else{
            i=n-1;
            while(i>=0){
                nr=nr*10+v[i];
                v[i]=0;
                i--;

            }
        }
        d=0;
        cnt=1;
        cdnr=nr;
        while(nr>1){
            rp=0;
            while(nr%nrp[d]==0){
                nr/=nrp[d];
                rp++;
            }
            cnt*=(rp+1);
            d++;
            if(nrp[d]*nrp[d]>nr){
                if(nr!=1)
                    cnt*=2;
                nr=1;
            }
        }
        if(cnt>max1){
            max1=cnt;
            cnr=cdnr;
        }else if(cnt==max1 && cdnr<cnr){
            cnr=cdnr;
        }
        nr=cnt;
        if(n-k>=0){
            poz=n-k;
            while(nr>0){
                v[poz]=nr%10;
                poz++;
                nr/=10;
            }
            n=n-(k-(poz-(n-k)));
        }else{
            n=0;
            while(nr>0){
                v[n]=nr%10;
                n++;
                nr/=10;
            }
        }
        cnt1++;
    }
    fout=fopen("divizori.out","w");
    fprintf(fout,"%d\n%d\n%d",cnt1+1,max1,cnr);
    fclose(fout);
    return 0;
}