Python Program for Linear Search

Problem: Given an array arr[] of n elements, write a function to search a given element x in arr[].
Examples :

Input : arr[] = {10, 20, 80, 30, 60, 50, 
                     110, 100, 130, 170}
          x = 110;
Output : 6
Element x is present at index 6

Input : arr[] = {10, 20, 80, 30, 60, 50, 
                     110, 100, 130, 170}
           x = 175;
Output : -1
Element x is not present in arr[].

A simple approach is to do linear search, i.e

• Start from the leftmost element of arr[] and one by one compare x with each element of arr[]
• If x matches with an element, return the index.
• If x doesn’t match with any of elements, return -1.

Example:

# Searching an element in a list/array in python # can be simply done using \'in\' operator # Example: # if x in arr: #   print arr.index(x)    # If you want to implement Linear Search in python    # Linearly search x in arr[] # If x is present then return its location # else return -1    def search(arr, x):        for i in range(len(arr)):            if arr[i] == x:             return i        return -1

The time complexity of above algorithm is O(n).

Please refer complete article on Linear Search for more details!