README.md

441. Arranging Coins

You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins.

Given n, find the total number of full staircase rows that can be formed.

n is a non-negative integer and fits within the range of a 32-bit signed integer.

Example 1:

n = 5 The coins can form the following rows: ¤ ¤ ¤ ¤ ¤ Because the 3rd row is incomplete, we return 2. 

Example 2:

n = 8 The coins can form the following rows: ¤ ¤ ¤ ¤ ¤ ¤ ¤ ¤ Because the 4th row is incomplete, we return 3. 

Solutions (Python)

1. Simulation

classSolution: defarrangeCoins(self, n: int) ->int: k=1whileTrue: n-=kifn<0: returnk-1k+=1

2. Mathematical

classSolution: defarrangeCoins(self, n: int) ->int: returnint(((1+8*n) **.5-1) /2)