Crivo + Fatorar em num primos

#include <cstdlib>
#include <iostream>
#include <stdio.h>
#include <cstring>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <map>
#include <stack>
#include <cmath>
#include <set>
#include <ctype.h>
#include <bitset>

#define INF 99999999
#define rep(i, a, b) for (int i = int(a); i < int(b); i++)
#define TRvii(c, it) for (vii::iterator it = (c).begin(); it != (c).end(); it++)
#define tr(it, s)  for ( typeof ( s.begin( ) ) it=s.begin( ); it!=s.end( ); it++ )
#define pb push_back
#define clr(a) memset((a),0,sizeof(a))
#define pi 3.1415926535897932384626433832795028841971
#define debug(x) cout << #x << " = " << x << endl;

using namespace std;

typedef long long ll;
typedef pair < int, int >  ii;
typedef vector < int >  vi;
typedef vector < ii >  vii;


int p[20000]; int e[20000]; int k;
int prime[200000]; int nprimes;

void factor(int n) {
    k = 0;
    for(int j=0; prime[j]*prime[j] <= n; ++j) if ( n%prime[j]==0 ) {
        p[k] = prime[j]; e[k] = 0;
        while ( n%prime[j]==0 ) { n/=prime[j]; e[k]++; }
        ++k;
    }
    if (n!=1) { p[k]=n; e[k] =1; ++k;}
}


void find_primes(int n) {

    nprimes = 1; prime[0] = 2; bool is_prime;
    for(int k=3;k<=n;k+=2) {
        is_prime = true;
        for(int j=0; j<nprimes && prime[j]*prime[j] <= k;++j)
            if (k%prime[j] == 0) {is_prime = false; break;}
        if ( is_prime ) prime[nprimes++] = k;
    }
}


int main(){

    find_primes(100);
    factor(99);

    rep(i,0,k+1)
        cout<<p[i]<<"^"<<e[i]<<endl;



    system("pause");
    return 0;
}