## Algorithm

Problem Name: 413. Arithmetic Slices

An integer array is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.

• For example, `[1,3,5,7,9]`, `[7,7,7,7]`, and `[3,-1,-5,-9]` are arithmetic sequences.

Given an integer array `nums`, return the number of arithmetic subarrays of `nums`.

A subarray is a contiguous subsequence of the array.

Example 1:

```Input: nums = [1,2,3,4]
Output: 3
Explanation: We have 3 arithmetic slices in nums: [1, 2, 3], [2, 3, 4] and [1,2,3,4] itself.
```

Example 2:

```Input: nums = 
Output: 0
```

Constraints:

• `1 <= nums.length <= 5000`
• `-1000 <= nums[i] <= 1000`

## Code Examples

### #1 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public int numberOfArithmeticSlices(int[] nums) {
int[] dp = new int[nums.length];
int count = 0;
for (int i = 2; i < dp.length; i++) {
if (nums[i] - nums[i - 1] == nums[i - 1] - nums[i - 2]) {
dp[i] = dp[i - 1] + 1;
count += dp[i];
}
}
return count;
}
}
``````
Copy The Code &

Input

cmd
nums = [1,2,3,4]

Output

cmd
3

### #2 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const numberOfArithmeticSlices = function(A) {
const arr = [];
let count = 0;
for (let i = 1; i < A.length - 1; i++) {
if (A[i] - A[i - 1] === A[i + 1] - A[i]) {
count += 1;
} else {
arr.push(count);
count = 0;
}
}
arr.push(count);
return arr.reduce((ac, el) => ac + calc(el), 0);
};

function calc(num) {
return (num * (num + 1)) / 2;
}

console.log(numberOfArithmeticSlices([1, 2, 3, 4]));
``````
Copy The Code &

Input

cmd
nums = [1,2,3,4]

Output

cmd
3