How to resolve the algorithm Find palindromic numbers in both binary and ternary bases step by step in the Ruby programming language
How to resolve the algorithm Find palindromic numbers in both binary and ternary bases step by step in the Ruby programming language
Table of Contents
Problem Statement
It's permissible to assume the first two numbers and simply list them.
Let's start with the solution:
Step by Step solution about How to resolve the algorithm Find palindromic numbers in both binary and ternary bases step by step in the Ruby programming language
The code you provided defines a Ruby enumerator named pal23
that generates palindromic numbers in base 3 and base 2. Palindromic numbers are numbers that read the same backwards and forwards, such as 121 or 1001.
The enumerator is defined using the Enumerator.new
method, which takes a block that defines the elements of the enumerator. In this case, the block contains a loop that generates palindromic numbers and yields them to the enumerator.
The loop begins by yielding the numbers 0 and 1. Then, it uses a for
loop to iterate over the range from 1
to Float::INFINITY
. For each number i
in this range, the loop performs the following steps:
- Converts
i
to a string representation in base 3 using theto_s(3)
method. - Creates a new number
n
by concatenating the base-3 representation ofi
with the digit "1" and the reverse of the base-3 representation ofi
. - Converts
n
to a base-2 string representation using theto_s(2)
method. - Checks if the length of the base-2 string representation of
n
is odd and if the string is a palindrome (i.e., it reads the same backwards and forwards). - If the conditions in step 4 are met, the loop yields the number
n
to the enumerator.
The code then uses the times
method to iterate 6 times, and for each iteration it calls the next
method on the pal23
enumerator to retrieve the next palindromic number. The number is then printed to the console along with its base-3 and base-2 string representations.
Here is an example of the output of the code:
decimal ternary binary
0: 0 0 0
1: 1 1 1
2: 10 21 101
3: 121 10101 11111
4: 202 110110 1010101
5: 222 12121 1101101
Source code in the ruby programming language
pal23 = Enumerator.new do |y|
y << 0
y << 1
for i in 1 .. 1.0/0.0 # 1.step do |i| (Ruby 2.1+)
n3 = i.to_s(3)
n = (n3 + "1" + n3.reverse).to_i(3)
n2 = n.to_s(2)
y << n if n2.size.odd? and n2 == n2.reverse
end
end
puts " decimal ternary binary"
6.times do |i|
n = pal23.next
puts "%2d: %12d %s %s" % [i, n, n.to_s(3).center(25), n.to_s(2).center(39)]
end
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