# Students Roll Number

#### CONCEPTS USED:

Basic Mathematics

Easy

#### PROBLEM STATEMENT`(`SIMPLIFIED`)`:

Given `N` seats, where English paper students are evenly placed `(0,2,4,...)` and Hindi paper students are oddly placed `(1,3,5,...)`. Print the roll number of English paper students.

See original problem statement here

#### For Example :

``````N = 5
Arr[] = [1, 2, 3, 4, 5]

Output: 1 3 5

Explanation: Students with roll number 1 3 5 are placed on even indexes i.e. 0 2 4.``````

#### SOLVING APPROACH:

1. Keep traversing the array and print the elements that are placed on even indices as the English paper students are sitting on roll numbers like `0`, `2`, `4` etc.

2. If the current index is a multiple of `2`, then print it else move ahead by referring Master algorithms online.

#### SOLUTIONS:

```
#include <stdio.h>

int main()
{
int t;
scanf("%d",&t);
while(t--)
{
int n;
scanf("%d",&n);
int arr[n];
for(int i=0;i<n;i++)
{
scanf("%d",&arr[i]);
if(i%2==0)
{
printf("%d ",arr[i]);
}
}
printf("\n");
}

return 0;
}

```
```
#include <bits/stdc++.h>
using namespace std;

int main()
{
int t;cin>>t;
while(t--)
{
int n;cin>>n;
int arr[n];
for(int i=0;i<n;i++)
{
cin>>arr[i];
if(i%2==0)
{
cout<<arr[i]<<" ";
}
}
cout<<"\n";
}

return 0;
}

```
```
import java.util.*;
import java.io.*;

public class Main {
public static void main(String args[]) throws IOException {
Scanner sc = new Scanner(System.in);
int t = sc.nextInt();
while(t!=0)
{
int n = sc.nextInt();
int arr[] = new int[n];
for(int i=0;i<n;i++)
{
arr[i] = sc.nextInt();
}
for(int i=0;i<n;i++)
{
if(i%2==0)
{
System.out.println(arr[i]);
}
}
System.out.println("");
t--;
}

}
}

```