Python data structure and algorithms

Python Data Structures & Algorithms – Full Notes
+ Solved Questions

1. Lists
• Ordered, mutable collection
• Example:


lst = [1, 2, 3]
lst.append(4)



2. Tuples
• Ordered, immutable


t = (1, 2, 3)



3. Sets
• Unordered, unique elements


s = {1, 2, 3}
s.add(4)



4. Dictionaries
• Key-value pairs


d = {"a":1, "b":2}




5. Stacks
• LIFO (Last In First Out)




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, stack = []
stack.append(1)
stack.pop()



6. Queues
• FIFO (First In First Out)


from collections import deque
q = deque()
q.append(1)
q.popleft()




7. Searching Algorithms

Linear Search


def linear_search(arr, x):
for i in range(len(arr)):
if arr[i] == x:
return i
return -1


Binary Search


def binary_search(arr, x):
low, high = 0, len(arr)-1
while low <= high:
mid = (low + high)//2
if arr[mid] == x:
return mid
elif arr[mid] < x:
low = mid + 1
else:
high = mid - 1
return -1




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