alg.rb

# Setup
array = [4, 2, 7, 11, 8, 24, 1, 0, 15, 33, 19, 21, 25, 3, 3, 5]


# Selection sort
def selection_sort(a)
  (a.length - 1).times do |outer|
    minimum = 100000000
    minimum_index = -1

    outer.upto(a.length - 1) do |inner|
      if minimum > a[inner]
        minimum = a[inner]
        minimum_index = inner
      end
    end

    a[outer], a[minimum_index] = a[minimum_index], a[outer]
  end
  return a
end


# Insertion sort
def insertion_sort(a)
  1.upto(a.length - 1) do |outer|
    prvek = a[outer]
    inner = outer - 1

    while inner >= 0 && a[inner] > prvek
      a[inner + 1] = a[inner]
      inner -= 1
    end

    a[inner + 1] = prvek
  end
  return a
end


# Bubble sort
def bubble_sort(a)
  begin
    sorted = true
    for x in (0..(a.length - 2))
      if a[x] > a[x + 1]
        a[x], a[x + 1] = a[x + 1], a[x]
        sorted = false
      end

    end
  end until sorted
  return a
end


# Heap sort
def build_heap(a)
  1.upto(a.length - 1) do |i|
    up(a, i)
  end
end

def up(a, i)
  son = i
  while son > 0
    father = (son - 1) / 2
    if a[father] < a[son]
      a[father], a[son] = a[son], a[father]
      son = father
    else
      return
    end

  end
end

def heap_sort(a)
  build_heap(a)
  index = a.length - 1
  while index > 0
    a[0], a[index] = a[index], a[0]
    index -= 1
    down(a, index)
  end
end

def down(a, index)
  father = 0
  while father * 2 + 1 <= index
    son = father * 2 + 1
    if son < index && a[son] < a[son + 1]
      son = son + 1
    end

    if a[father] < a[son]
      a[father], a[son] = a[son], a[father]
      father = son
    end

  end
end

#nejhur n x m, prumerne n + m
def string_search(kupka, jehla)
  (kupka.length - jehla.length).times do |i|
    j = 0

    while j < jehla.length && kupka[i + j] == jehla[j]
      j += 1
    end
    if j == jehla.length
      return i
    end
  end
  return "nenaslo se"
end


kupka = "nenavidim algoritmy z celeho srdce, ale chci se zlepsit a tak se je naucim a dostanu jednicku "
jehla = "jednicku"

p string_search(kupka, jehla)