PFactors

#include<stdio.h>
int primes[10000000];
int pf[10000000];
void calcPrimes(int n){
    int index=0;
    primes[1]=1;
    primes[0]=1;
    int i=2,j=0,lastind=0;
    for(i=2;i*i<=n;i++){
        if(primes[i]==0){
            for(j=i*i;j<n;j+=i){
                primes[j]=i;
            }
            primes[i]=i;
            lastind=i;
        }
    }
    for(i=lastind+1;i<=n;i++)
        if(primes[i]==0)
            primes[i]=i;
}
void printfactors(int n){
    int temp[n];
    int index=0;
    while(n>1){
        temp[index++]=primes[n];
        n/=primes[n];
    }
    int i;
    for(i=index-1;i>0;i--){
        printf("%d x ",temp[i]);
    }
    printf("%d\n",temp[0]);
}
main(){
    int number;
    calcPrimes(10000000);
    while(1){
        scanf("%d",&number);
        if(number==0) return 0;
        else if(number > 0) {
            printf("%d = ",number);
            printfactors(number);
        }else {
            printf("%d = -1 x ",number);
            number *=-1;
            printfactors(number);
        }
    }
    return 0;
}