Walkthrough

Solutions

def capitalize_each_word(str)
  words = str.split
  capitalized_words = []

  words.each do |word|
    capitalized_words << word.capitalize
  end

  capitalized_words.join(" ")
end

def compute_squares(arr)
  squares = []

  arr.each do |element|
    squares << element ** 2
  end

  squares
end

def two_sum_to_zero?(arr)
  arr.each_index do |idx|
    arr_without_el = arr[0...idx] + arr[idx+1...arr.length] # ensuring we don't examine the same element twice
    return true if arr_without_el.include?(arr[idx] * -1)
  end

  false
end

def longest_word(str)
  words = str.split
  longest_word = ""

  words.each do |word|
    if word.length > longest_word.length
      longest_word = word
    end
  end

  longest_word
end

#Alternate solutions using while-loops

def capitalize_each_word(str)
  arr = str.split
  i = 0
  while i < arr.length
    arr[i] = arr[i].capitalize
    i += 1
  end
  arr.join(" ")
end

def compute_squares(arr)
  i = 0
  while i < arr.length
    arr[i] = arr[i] ** 2
    i += 1
  end
  arr
end

def two_sum_to_zero?(arr)
  i = 0
  while i < arr.length
    others = arr[0...i] + arr[(i+1)..-1]
    return true if others.include?(0 - arr[i])
    i += 1
  end
  false
end

def longest_word(str)
  arr = str.split
  longest = arr.first
  i = 1
  while i < arr.length
    if arr[i].length > longest.length
      longest = arr[i]
    end
    i += 1
  end
  longest
end