# Write a program to check number is even or odd .

Given a number we have to find whether number is even or odd without using mod operator.

So what is even and odd number?

Even Number: number that is divisible by 2.

odd number:number that is not divisble by 2.

Example:

``````input:28
output:even

input:37
output:odd``````

there are two approach to find even and odd number

1-by using mod operator.

2-by using xor operator.

Approach 1:using modulus operator.

```#include<iostream>
using namespace std;
int main()
{
int number;
cout<<"enter a number "<<endl;
cin>>number;

if(number%2==0)
{
cout<<"number is even "<<endl;
}
else
{
cout<<"number is odd "<<endl;
}
}```
```enter a number :69
number is odd.```

Approach 2 : by using xor operator.

Logic:

``main idea is to check whether the last bit of number is set or not.``

```#include<iostream>
using namespace std;
bool even(int number)
{

return (!(number&1));
//if it is true then it is even otherwise it is false
}
int main()
{
int number;
cout<<"enter a number "<<endl;
cin>>number;
if(even(number)==true)
{
cout<<"number is even "<<endl;
}
else
{
cout<<"number is odd "<<endl;
}
}```
```enter a number :72
number is even ```

Time Complexity:O(1)

space complexity:O(1)

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