1.py

# 1502. Can Make Arithmetic Progression From Sequence
# User Accepted:6264
# User Tried:6356
# Total Accepted:6398
# Total Submissions:7832
# Difficulty:Easy
# Given an array of numbers arr. A sequence of numbers is called an arithmetic progression if the difference between any two consecutive elements is the same.
# Return true if the array can be rearranged to form an arithmetic progression, otherwise, return false.

# Example 1:
# Input: arr = [3,5,1]
# Output: true
# Explanation: We can reorder the elements as [1,3,5] or [5,3,1] with differences 2 and -2 respectively, between each consecutive elements.

# Example 2:
# Input: arr = [1,2,4]
# Output: false
# Explanation: There is no way to reorder the elements to obtain an arithmetic progression.
 
# Constraints:
# 2 <= arr.length <= 1000
# -10^6 <= arr[i] <= 10^6

class Solution:
    def canMakeArithmeticProgression(self, arr: List[int]) -> bool:
        arr.sort()
        gap = arr[1] - arr[0]
        for i in range(1, len(arr)):
            if arr[i] - arr[i-1] != gap:
                return False
        return True