examples.md

Examples

Snippet EX-A - Big O: O(n) because as the data set size grows the amount of loop iterations grows linearly

(1..data.length).each do
  puts "hello"
end

Snippet EX-B - Big O: O(n) because even though there is a loop inside of a loop here, the inside loop runs a fixed number of times making it constant time, and only the outer loop grows linearly

(1..data.length).each do
  (1..10).each do
    puts "hello"
  end
end

Snippet EX-C - Big O: O(n^2) because we have a O(n) loop inside a O(n) loop which means that we multiply them to get O(n^2)

(1..data.length).each do
  (1..data.length).each do
    puts "hello"
  end
end

Snippet EX-D - Big O: O(n^2) because in the worst case (i=1) the inner loop runs O(n) times and the outer loop runs O(n), which we multiply to be O(n^2)

(1..data.length).each do |i|
  (i..data.length).each do
    puts i
  end
end

Snippet EX-E - Big O: O(n * m) because the two loops do not depend on each other but both run linearly in time

(1..data.length).each do
  (1..otherdata.length).each do
    puts "hello"
  end
end

Snippet EX-F - Big O: O(n * m) because for every element in the data array (n) we must visit every element in the hash for that element (m).

data.each do |item|
  item.each do |key, value|
    puts "#{key} maps to #{value}"
  end
end

Snippet EX-G - Big O: O(n) because in order to get all the keys in the hash, we must visit every element one time, which is a linear operation

puts hash.keys

Snippet EX-H - Big O: O(n) because the first set of nested loops is O(n) * O(1) = O(n) and then the next sequential loop is also O(n), but because they are not nested, we just choose the 'worst' case (though they are the same in this case)

data.each do |i|
  3.times do
    puts i
  end
end
data.each do
  puts "hello"
end