# 2579. Count Total Number of Colored Cells """ there exists an infinitely large two-dimensional grid of uncoloured unit cells. you are given a positive integer 'n', indicating that you must do the following routine for 'n' minutes: at the first minute, colour any arbitrary unit cell blue, and every minute thereafter, colour blue every uncoloured cell that touches a blue cell. """ class Solution(object): def coloredCells(self, n): """ :type n: int :rtype: int """ return 1 + 4 * sum(range(n)) if __name__ == "__main__": obj = Solution() print(obj.coloredCells(n=1)) print(obj.coloredCells(n=2))