Binary Search (1)

For Example, the data is:
The key is 6

Record	[1]	[2]	[3]	[4]	[5]
Data	2	5	21	1	6

First step: the data must be sorting. This sample, we can sort the data with bubble sort methods.

Record	[1]	[2]	[3]	[4]	[5]
Data	2	5	21	1	6
Step 1	2	5	21	1	6	2 and 5, no Exchange
	2	5	21	1	6	2 and 21, no Exchange
	1	5	21	2	6	2 and 1, Exchange
Step 2	1	5	21	2	6	5 and 21, no Exchange
	1	2	21	5	6	2 and 5, Exchange
Step 3	1	2	5	21	6	5 and 21, Exchange
Step 4	1	2	5	6	21	21 and 6, Exchange

Second step: we can search data key 6 with binary search

New data:

Record	[1]	[2]	[3]	[4]	[5]
Data	1	2	5	6	21

Step [1]:

                (low+high) div 2 =  (1+5) div 2

                                            =  6 div 2

                                            =  3---> middle

                the data on the record [3] is 5, then 5<6, next step swipe right

	low		middle		high
Record	[1]	[2]	[3]	[4]	[5]
Data	1	2	5	6	21

Step [2]:  new_low = middle +1 = 3 +1 = 4

				new_low	high
Record	[1]	[2]	[3]	[4]	[5]
Data	1	2	5	6	21

                 

               (new_low + high) = (4+5) div 2

                                             = 9 div 2

                                             = 4

                the data on the record [4] is 6, then 6=6 , end.