Array ( [0] => [1] => questions [2] => Arrays [3] => Arithmetic-Progression ) Arrays | Arithmetic Progression | THE INQUISITIVE

### Arithmetic Progression

#### Description

Given list of elements. You have to find the sum of elements which are in AP.

#### Input Format

First line contains a number N. Next line contains N integers separated by spaces.

#### Output Format

Print the resultant sum value.

Example 1:

Input
```5
1 2 3 4 5```
Output
`15`
Example 2:

Input
```8
0 2 4 6 8 10 12 14```
Output
`56`
Example 3:

Input
```10
1 4 7 10 13 16 19 22 25 28```
Output
`145`

### Approach

Approach-1:

Step-i)Traverse the array and check whether difference between adjacent elements is same or not
Step-ii) If not return "Given array is not in AP"
Step-iii)Else initialize sum variable to 0
Step-iv) Traverse the array and keep adding elements to the sum variable
Step-v) Return the sum

Time Complexity: O(n)
Space Complexity: O(1)

Note :

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