Solution:
/*************************************
******** Team : BUBT_HIDDEN **********
**************************************
*********** Shipu Ahamed *************
*** http://shipuahamed.blogspot.com **
*************************************/
#include
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#include
#include
#include
#include
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#include
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#include
#define sc scanf
#define pf printf
#define ll long long
#define pi 2*acos(0.0)
#define ff first
#define se second
#define inf (1<<30) //infinity value
#define pb push_back
#define mod 1000000007
#define ST(v) sort(v.begin(),v.end())
#define cover(a,d) memset(a,d,sizeof(a))
#define input freopen("in.txt","r",stdin)
#define output freopen("out.txt","w",stdout)
#define maxall(v) *max_element(v.begin(),v.end())
#define minall(v) *min_element(v.begin(),v.end())
#define un(v) ST(v), v.erase(unique(v.begin(),v.end()),v.end())
using namespace std;
int main()
{
ll n;
while(cin>>n)
{
if(n==0) break;
pf("%lld = ",n);
if(n<0)
{
pf("-1 x ");
n=-1*n;
}
ll l=sqrt(n);
for(ll i=2;i<=l;i=i++)
{
while(n%i==0)
{
pf("%lld",i);
n=n/i;
if(n>1)
pf(" x ");
}
}
if(n>1)
pf("%lld",n);
pf("\n");
}
return 0;
}
https://github.com/Shipu/OnlineJudgeProblemSolutionWithCPlusPlus/tree/master/uva/583/583.cpp