# Linear Search in Python

Note

If you want to understand Linear Search in detail then refer to the Linear Search Algorithm article.

## Linear Search Algorithm

Let us assume that we have an unsorted array `A[]`

containing `n`

elements, and we want to find an element - `X`

.

##### Traverse all elements inside the array starting from the leftmost element using a

`for`

loop and do the following:- If the value of
`A[i]`

matches with`X`

, then return the index`i`

. (If there can be multiple elements matching`X`

, then instead of returning the index`i`

, either print all indexes or store all the indexes in an array and return that array.) - Else move on to the next element.
- If it is at the last element of the array, quit the
`for`

loop.

- If the value of
##### If none of the elements matched, then return

`-1`

.

## Linear Search Python Implementation

```
def linearsearch(arr, n, x):
for i in range(0, n):
if (arr[i] == x):
return i
return -1
arr = [1, 2, 3, 4, 5]
x = 1
n = len(arr)
position = linearsearch(arr, n, x)
if(position == -1):
print("Element not found !!!")
else:
print("Element is present at index", position)
```

Output:

```
Element is found at index: 1
```

The time complexity of the above algorithm is `O(n)`

.

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