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12 changes: 9 additions & 3 deletions lib/fibonacci.rb
Original file line number Diff line number Diff line change
@@ -1,8 +1,14 @@
# Improved Fibonacci

# Time Complexity - ?
# Space Complexity - ? (should be O(n))
# Time Complexity - O(n!)
# Space Complexity O(n)
# Hint, you may want a recursive helper method
def fibonacci(n)

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This is the brute force O(2n) time complexity solution...


if n < 0
raise ArgumentError, "Invalid number"
elsif n == 0 || n == 1
return n
else
return fibonacci(n - 2) + fibonacci(n - 1)
end
end
28 changes: 24 additions & 4 deletions lib/super_digit.rb
Original file line number Diff line number Diff line change
@@ -1,10 +1,30 @@
# Superdigit

# Time Complexity - ?
# Space Complexity - ?
def super_digit(n)

# Time Complexity - O(n)
# Space Complexity - O(n)
Comment on lines +3 to +4

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Yes, where n is the number of digits.

def super_digit(x)

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👍

if x < 10
return x
elsif
sum = integer_calcuation(x)
super_digit(sum)
end
end

def integer_calcuation(x)

digit_array = x.to_s.split('')

sum = 0

digit_array.each do |element|
sum += element.to_i
end

return sum
end




# Time Complexity - ?
Expand Down
4 changes: 2 additions & 2 deletions test/super_digit_test.rb
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
require_relative "test_helper"

xdescribe "super_digit" do
describe "super_digit" do
it "will return 2 for super_digit(9875)" do
# Act
answer = super_digit(9875)
Expand Down Expand Up @@ -33,7 +33,7 @@
expect(answer).must_equal 6
end

describe "refined superdigit" do
xdescribe "refined superdigit" do
it "will return 1 for n = 1 and k = 1" do
# Act
answer = refined_super_digit(1, 1)
Expand Down