Smallest Even number with N digits

Given a number N, the task is to find the smallest Even number with N digits.
Examples:

Input: N = 1
Output: 0

Input: N = 2
Output: 10 

Approach: 
Case 1 : If N = 1 then answer will be 0. 
Case 2 : if N != 1 then answer will be (10^(N-1)) because the series of smallest even numbers will go on like, 0, 10, 100, 1000, 10000, 100000, …..
Below is the implementation of the above approach: 

C++

// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;

// Function to return smallest even
// number with n digits
int smallestEven(int n)
{
    if (n == 1)
        return 0;
    return pow(10, n - 1);
}

// Driver Code
int main()
{

    int n = 4;
    cout << smallestEven(n);

    return 0;
}

Java

// Java implementation of the approach
class Solution {

    // Function to return smallest even
    // number with n digits
    static int smallestEven(int n)
    {
        if (n == 1)
            return 0;
        return Math.pow(10, n - 1);
    }

    // Driver code
    public static void main(String args[])
    {
        int n = 4;
        System.out.println(smallestEven(n));
    }
}

Python3

# Python3 implementation of
# the approach

# Function to return smallest
# even number with n digits
def smallestEven(n) :

    if (n == 1):
        return 0
    return pow(10, n - 1)

# Driver Code
n = 4
print(smallestEven(n))

# This code is contributed
# by ihritik.

C#

// C# implementation of the approach
using System;
class Solution {

    // Function to return smallest even
    // number with n digits
    static int smallestEven(int n)
    {
        if (n == 1)
            return 0;
        return Math.pow(10, n - 1);
    }

    // Driver code
    public static void Main()
    {
        int n = 4;
        Console.Write(smallestEven(n));
    }
}

PHP

<?php
// PHP implementation of the approach

// Function to return smallest
// even number with n digits
function smallestEven($n)
{
    if ($n == 1)
        return 0;
    return pow(10, $n - 1);
}

// Driver Code
$n = 4;
echo smallestEven($n);

// This code is contributed
// by ihritik.
?>

Javascript

<script>
// Javascript implementation of the approach

// Function to return smallest even
// number with n digits
function smallestEven(n)
{
    if (n == 1)
        return 0;
    return Math.pow(10, n - 1);
}

// Driver Code
var n = 4;
document.write(smallestEven(n));

// This code is contributed by rrrtnx.
</script>

Output:

1000

Time Complexity: O(log n).