LeetCode in Kotlin

441. Arranging Coins

Easy

You have n coins and you want to build a staircase with these coins. The staircase consists of k rows where the ith row has exactly i coins. The last row of the staircase may be incomplete.

Given the integer n, return the number of complete rows of the staircase you will build.

Example 1:

Input: n = 5

Output: 2

Explanation: Because the 3^rd row is incomplete, we return 2.

Example 2:

Input: n = 8

Output: 3

Explanation: Because the 4^th row is incomplete, we return 3.

Constraints:

• 1 <= n <= 231 - 1

Solution

class Solution {
    fun arrangeCoins(n: Int): Int {
        var i = 1
        var x = n
        while (x > 0) {
            x -= ++i
        }
        return i - 1
    }
}

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