Program to find the nearest smaller or larger prime number from the given number.

near_prime.rb

def is_prime(num)
     i=2
     res = true
     while i < num
        if num % i == 0
            res =  false
             break
        end
        i+=1
    end
    
    return res
end

def nearest_smaller_prime(num)
    if is_prime(num) == true
        return num
    else
        num = num -1
        new_pr = nearest_smaller_prime(num)
    end
    
end

def nearest_larger_prime(num)
    
    if is_prime(num) == true
        return num
    else
        num = num +1
        new_pr = nearest_larger_prime(num)
    end
    
end



inp = Integer(gets)

puts "#{nearest_larger_prime(74)}"
puts "#{nearest_smaller_prime(78)}"