### Binary Search in Data Structure

Binary search the array is divided into two equal part. The element is compared

with middle element. If it is smaller, it is searched in first half, but if the middle is

bigger, it is searched in second half. This is repeated and in next stage we have

to search only in one quarter of list and so on.

#### Advantage

In binary search method, searching is faster as comparison to linear search.

#### Disadvantage

Binary search method is applicable only on sorted list

##### Algorithm

Binary search (A, LB, UB, DATA, LOC)

**Step 1**

Set FIRST = LB

Set LAST = UB

MID = INT[FIRST + LAST]/2

**Step 2.**

Repeat step 3 and 4 while

LAST >= FIRST and A[MID] =/ DATA

**Step 3**

If DATA < A[MID] then
Set LAST = MID-1
Else
Set FIRST = MID +1
**Step 4**

Set MID = INT[FIRST+LAST]/2

**Step 5**

If A[MID] = DATA then

Set LOC = MID

else

Set LOC = NULL

**Step 6**

EXIT