Converting Decimal To Binary

Code:

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pi acos(-1)

ll bin(ll num)
{
    ll temp,i,s;
    temp=num;
    i=1;
    s=0;
    while(temp)
    {
      s+=(temp%2)*i;
      i=i*10;
      temp/=2;
    }
    return s;
}

int main()
{
    ll num;
    cin>>num;
    cout<<bin(num)<<endl;
}

Output:

1234
10011010010

Process returned 0 (0x0)   execution time : 2.942 s
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