POJ1730 Perfect Pth Powers (math)

you can find the original description here

This problem let us to find whether can be exactly a number ‘s k power,we can have the given number x to depart with prime factor,and we let answer be the gcd of all exponent , and we need to take care of the negative number just make sure that the answer is odd.

#include <iostream>
#include <vector>
#include <cstring>
#include <algorithm>
#define ll __int64
using namespace std;
const int N = 1e6+1;
vector<int> prime;
int notprime
;
void ola_prime()
{
notprime[1] = 1;
for(int i = 2; i<N; i++)
{
if(notprime[i] == 0)
{
prime.push_back(i);
}
for(int j = 0; j<prime.size() && prime[j]* i <N ; j++)
{
notprime[prime[j]*i] = 1;
if(i % prime[j] == 0)
{
break;
}
}
}
}
int main()
{

ola_prime();
ll n = 0;
while(cin>>n)
{
if(!n) break;
int ans = 0,sig = 1;
if(n<0)
{
sig = 0;
n = -n;
}
int e = 0;
for(int i = 0;i<prime.size() && prime[i] <= n;i++)
{
if(n%prime[i] == 0)
{
e = 0;
while(n%prime[i] == 0)
{
n/=prime[i];
e++;
}
ans = __gcd(ans,e);
}
}
if(n >1) ans = __gcd(ans,1);
if(!sig)
{
while(ans%2 == 0) ans/=2;
}
cout<<ans<<endl;
}

return 0;
}
/*
4
3 7
4 1
2 1
8 1
3 7
4 2
2 1
8 4
3 5
4 1
2 2
8 9
1 1
10 3
*/