codertcet111

#Author: Shubham Mishra

class TreeNode
  attr_accessor :value, :left, :right

  def initialize(value)
    @value = value
    @left = nil
    @right = nil
  end

codertcet111

#Author: Shubham Mishra

def merge_sort(arr)
  # Base case: If the array has only one element or is empty, it is already sorted
  return arr if arr.length <= 1

  # Divide the array into two halves
  mid = arr.length / 2
  left_half = arr[0...mid]
  right_half = arr[mid..]

codertcet111

#Author: Shubham Mishra

def quick_sort(arr)
  return arr if arr.length <= 1

  # Choose the pivot element (for simplicity, we'll use the last element)
  pivot = arr.pop
  left = []
  right = []

codertcet111

#Authore: Shubham Mishra

def heap_sort(arr)
  n = arr.length

  # Build a binary heap from the array
  (n / 2 - 1).downto(0) do |i|
    heapify(arr, n, i)
  end

codertcet111

#Author: Shubham Mishra
#Table 
Approval: assignee_id, deleted_at, is_visible, status, ...

#Query:
result = ActiveRecord::Base.connection.execute('
  EXPLAIN ANALYZE
  SELECT "approvals"."request_type"
  FROM "approvals"
  WHERE "approvals"."deleted_at" IS NULL

codertcet111

results = ActiveRecord::Base.connection.execute("
    SELECT
    idstat.relname AS TABLE_NAME,
    indexrelname AS index_name,
    idstat.idx_scan AS index_scans_count,
    pg_size_pretty(pg_relation_size(indexrelid)) AS index_size,
    tabstat.idx_scan AS table_reads_index_count,
    tabstat.seq_scan AS table_reads_seq_count,
    tabstat.seq_scan + tabstat.idx_scan AS table_reads_count,
    n_tup_upd + n_tup_ins + n_tup_del AS table_writes_count,

codertcet111

#Author: Shubham Mishra
#I/O: puts length_of_longest_substring("abcabcbb")
#O/P: 3


#Solution 1: Time optimised solution
def length_of_longest_substring(s)
    i, j = 0, 0
    sub_s = s[0]
    max = 0

codertcet111

#Author: Shubham Mishra
#I/O: puts longest_palindrome("abbdbebffbebshsj")
#O/P: bebffbeb

def longest_palindrome(s)
    return s if s.length == 1
    st, en = 0, s.length - 1
    max = 0
    sub_s = ""
    sub_s_arr = []

codertcet111

# config/initializers/active_record_query_timeout.rb

# Set statement timeout for each query
if ActiveRecord::Base.connection_config[:adapter] == 'postgresql'
  ActiveRecord::Base.connection.execute("SET statement_timeout = '10000';") # 10 seconds

  ActiveRecord::MigrationContext.prepend(Module.new do
    def initialize(*args)
      super
      ActiveRecord::Base.connection.execute("SET statement_timeout = '0';")

codertcet111

if ActiveRecord::Base.connection_config[:adapter] == 'postgresql'
  ActiveRecord::Base.connection.execute("SET statement_timeout = '10000';") # 10 seconds

  # Register an before migration callback to reset the timeout to 0 which means no timeout
  ActiveRecord::Migration.before_migrate do
    ActiveRecord::Base.connection.execute("SET statement_timeout = '0';")
  end

  ActiveRecord::Migration.after_migrate do
    ActiveRecord::Base.connection.execute("SET statement_timeout = '10000';")