To write a program to perform linear search and binary search using python programming.
- Hardware – PCs
- Anaconda – Python 3.7 Installation / Moodle-Code Runner
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Start from the leftmost element of array[] and compare k with each element of array[] one by one.
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If k matches with an element in array[] , return the index.
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If k doesn’t match with any of elements in array[], return -1 or element not found.
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Set two pointers low and high at the lowest and the highest positions respectively.
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Find the middle element mid of the array ie. arr[(low + high)/2]
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If x == mid, then return mid.Else, compare the element to be searched with m.
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If x > mid, compare x with the middle element of the elements on the right side of mid. This is done by setting low to low = mid + 1.
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Else, compare x with the middle element of the elements on the left side of mid. This is done by setting high to high = mid - 1.
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Repeat steps 2 to 5 until low meets high
i) #Use a linear search method to match the item in a list.
'''
Program for linear search method to match the item in a list
Developed by: lakshmi mounika
RegisterNumber: 23004124
'''
def linearSearch(array,n,k):
for i in range(0,n):
if(array[i]==k):
return i
return -1
array = eval(input())
k = eval(input())
n=len(array)
array.sort()
result=linearSearch(array,n,k)
if(result==-1):
print(array)
print("Element not found")
else:
print(array)
print("Element found at index: ",result)
ii) # Find the element in a list using Binary Search(Iterative Method).
'''
Program to find the element in a list using Binary Search(Iterative Method)..
Developed by: lakshmi mounika
RegisterNumber: 23004124
'''
def binarySearchIter(array, k, low, high):
while low<=high:
mid=low+(high-low)//2
if array[mid]==k:
return mid
elif array[mid]<k:
low=mid+1
else:
high=mid-1
return -1
array=eval(input())
array.sort()
k=eval(input())
result=binarySearchIter(array,k,0,len(array)-1)
if(result==-1):
print(array)
print("Element not found")
else:
print(array)
print("Element found at index: ",result)
iii) # Find the element in a list using Binary Search (recursive Method).
'''
Program to find the element in a list using Binary Search (recursive Method).
Developed by: lakshmi mounika
RegisterNumber: 23004124
'''
def BinarySearch(arr, k, low, high):
if high>=low:
mid=low+(high-low)//2
if arr[mid]==k:
return mid
elif arr[mid]>k:
return BinarySearch(arr,k,low,mid-1)
else:
return BinarySearch(arr,k,mid+1,high)
else:
return -1
arr = eval(input())
arr.sort()
k = eval(input())
result=BinarySearch(arr,k,0,len(arr)-1)
if(result==-1):
print(arr)
print("Element not found")
else:
print(arr)
print("Element found at index: ",result)
Thus the linear search and binary search algorithm is implemented using python programming.