arithmeticsubarrays.py

#1630
#medium


#A sequence of numbers is called arithmetic if it consists of at least two elements, and the difference between every two consecutive elements is the same. More formally, a sequence s is arithmetic if and only if s[i+1] - s[i] == s[1] - s[0] for all valid i.

#For example, these are arithmetic sequences:

#1, 3, 5, 7, 9
#7, 7, 7, 7
#3, -1, -5, -9
#The following sequence is not arithmetic:

#1, 1, 2, 5, 7
#You are given an array of n integers, nums, and two arrays of m integers each, l and r, representing the m range queries, where the ith query is the range [l[i], r[i]]. All the arrays are 0-indexed.

#Return a list of boolean elements answer, where answer[i] is true if the subarray nums[l[i]], nums[l[i]+1], ... , nums[r[i]] can be rearranged to form an arithmetic sequence, and false otherwise.



#my own solution using python3:

class Solution:
    def checkArithmeticSubarrays(self, nums: List[int], l: List[int], r: List[int]) -> List[bool]:
        res = []
        for i in range(len(l)):
            window = nums[l[i]: r[i] + 1]
            print(window)
            flag = True
            w = sorted(window)
            for j in range(1, len(w) - 1):
                if abs(w[j] - w[j - 1]) != abs(w[j + 1] - w[j]):
                    flag = False
            res.append(flag)
        return res