Teach Binary Search Algorithm with example

Teach Binary Search Algorithm with example

• 1.
  BINARY SEARCH ALGORITHM
• 2.
  Searching
• 3.
  What is searching? ■ Searching is a process used to find the location of a target among a list of objects. e.g., where is 14?
• 4.
  Successful searching in an unorderedlist
• 5.
  Unsuccessful search in unordered list
• 6.
  Search Algorithms 6
• 7.
  Binary Search O(log2n) ■A binary search looks for an item in a list using a divide- and-conquer strategy 7
• 8.
  Binary Search ◻Binary searchalgorithm assumes that the items in the array being searched are sorted ◻We start by dividing the array into 2 parts and look look for the item in the middle of the array in a binary search ◻If the item we are searching is less than the item in the middle, we know that the item won’t be in the second half of the array. So we look in the 1st half ◻Once again we examine the middle element ◻The process continues with each comparison cutting in half the portion of the array until we reach the location the item might be
• 9.
  • Determine whether22 is in the list Binary Search Algorithm Example Array list with twelve (12) elements 21 is less than 22, so we look in the 2nd half
• 10.
  Binary Search Algorithm(Cont’d) Search list, list[6] … list[11] first = mid + 1
• 11.
  Binary search example 11 Mid =(6+11)/2 =8
• 12.
  Unsuccessful binary search example 12
• 13.
  Binary Search 13
• 14.
  Binary Search 14
• 15.
  15