Implement the basic algorithm in Python to deepen your understanding of the algorithm. As the ninth bullet, we deal with linear search.
Search: Finding the data you want from a lot of data Linear: Examine in order from the beginning
In other words, linear search does not do anything complicated, but searches from the front in order.
Store the data in the list and check it in order from the beginning. This is a very simple program structure and easy to implement ⇒ ** Effective method when the number of data is small **
The code of the linear search and the output at that time are shown below.
linear_search.py
"""
2020/12/21
@Yuya Shimizu
Linear search
"""
#Linear search function
def linear_search(data, target):
for i in range(len(data)):
if data[i] == target:
return i
return False
if __name__ == '__main__':
data = [50, 20, 70, 60, 40, 90, 30] #Target data to be searched
target = 40 #Value to search
found = linear_search(data, target)
if not found:
print(f"{target} is not found in the data")
else:
print(f"{target} is found at data[{found}]")
40 is found at data[4]
Next, the output result when False is returned is also shown.
45 is not found in the data
It is turned by the for statement, but since we want to return the index of the data as the return value, we dare to usefor i in range (len (data)). Also, by return in for, it can be expressed by simply writing return False outside the for statement that the search result cannot be found.
Linear search is very simple and overlaps with intuition. I think it will be the basis for other searches. I am looking forward to learning from now on.
Introduction to algorithms starting with Python: Standards and computational complexity learned with traditional algorithms Written by Toshikatsu Masui, Shoeisha
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