Nitesh-Mishra

# check balanced parentheses in ruby :
#
# $ ruby check_balanced_parentheses.rb
# Enter string : 
# ((()))
# true

def check_balanced_parentheses?(entered_string)
  stack = []
  entered_string.chars.each do |token|

Nitesh-Mishra

# Given an array of integers, find the 3 numbers that sum up to a target number.
# ruby find_3_Numbers_that_sum_to_target_number.rb
# Enter the size of array : 5
# Enter 1 element : 
# 1
# Enter 2 element :
# 2
# Enter 3 element :
# 3
# Enter 4 element :

Nitesh-Mishra

# Roots of quadratic equation
#
# $ ruby roots_of_quadratic_equations.rb
# Equation will be in the format : ax^2 + bx + c
# Enter the value of a :
# 2
# Enter the value of b :
# 3
# Enter the value of c :
# 4

Nitesh-Mishra

#Swapping two variables in ruby :
#
# $ ruby swap_two_variables.rb
# Enter first variable :
# 2
# Enter second variable :
# 3
# After exchanging the value :
# the value of a is :3
# the value of b is :2

Nitesh-Mishra

# selection_sort.rb
#
# $ ruby selection_sort.rb
# [1, 2, 3, 4, 5, 6, 7, 8]

def selection_sort(array)
  n = array.length-1
  for i in 0..n-1
    min = i
    j = i + 1

Nitesh-Mishra

# quick_sort.rb
#
# $ ruby quick_sort.rb
# [1, 2, 3, 4, 5, 6, 7, 8]

def quicksort(array)
  return array if array.length <= 1
  pivot_index = (array.length / 2).to_i
  pivot_value = array[pivot_index]
  array.delete_at(pivot_index)

Nitesh-Mishra

# merge_sort.rb
#
# $ ruby merge_sort.rb
# [1, 2, 3, 4, 5, 6, 7, 8]

def merge_sort(array)
  n = array.length
  if n > 1
    mid = n/2
    lefthalf = array[0..mid-1]

Nitesh-Mishra

# insertion_sort.rb
#
# $ ruby insertion_sort.rb
# [1, 2, 3, 4, 5, 6, 7, 8]

def insertion_sort(array)
  for i in 1..array.length - 1
    j = i
    temp = array[i]
    while ((j>0) and (array[j-1] > temp))

Nitesh-Mishra

# bubble_sort.rb
#
# $ ruby bubble_sort.rb
# [1, 2, 3, 4, 5, 6, 7, 8]

def bubble_sort(array)
  for i in 0..array.length - 1
    for j in 0..array.length - 2
      if array[j] > array[j+1]
	array[j],array[j+1] = array[j+1],array[j]