Leetcode 413. Arithmetic Slices

class Solution:
    def numberOfArithmeticSlices(self, nums: List[int]) -> int:
        n = len(nums)
        count = 0
        diff = 0
        pre = 10000
        temp = 0
        for i in range(1, n):
            diff = nums[i] - nums[i-1]
            if diff == pre:
                temp += 1
                count += temp
            else:
                temp = 0
            pre = diff
        return count