Sorting Algorithm

sorting.md

Sort the following sequence

[69,81,30,38,9,2,47,61,32,79]

Some common sorting algorithms

• Selection Sort Wiki
• Insertion Sort Wiki
• Bubble Sort Wiki
• Quick Sort Wiki

Selection Sort

It tries to find the smallest number and put it at the front.

def selectionsort(list)  
  list.size.times do |start|  
    min = start  
    start.upto(list.size-1) do |i|  
      min = i if list[i] < list[min]  
    end  
    list[start], list[min] = list[min], list[start]  
  end  
  list  
end 

Bubble Sort

It goes through the whole sequence, in order to compare the two elements next to each other. Biggest number would go to the end of sequence first.

• Your time

Resources

• 15 Sorting Algorithms in 6 Minutes
• Sorting Algorithm

def bubble_sort(array)
  return array if array.size == 1
  swapped = true
  while swapped do #this will loop through the below block until everything has been swapped
    swapped = false
    0.upto(array.size - 2) do |i| # -2 because the last iteration would be for the last two elements
      if array[i+1] < array[i]
        array[i+1], array[i] = array[i], array[i+1]
        swapped = true
      end
    end
  end
  array
end