Project Euler 3 - Highest Prime Factor

Question

before I start I want to clarify that I am not looking for code examples to get the answer; that would defeat the object of Project Euler.

The problem

Answer 1

# Possible solution  but still its *time consuming* but answer can be guessed by the last option in console output 

#include
#include
#include
#include 
int prime(unsigned long long); 
using namespace std; 
int main(){ 
unsigned long long ii, ij; unsigned long long in; 
cin>>in; ij = ceil(in/2); 
if( (ij % 2) == 0 ) ij -= 1; 
for(ii = 3 ;ii < ij;ii+= 2){
if(in % ii == 0){
        if(prime(ii) == 1 ){
    cout<<" ans "<