441. Arranging Coins
Easy
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.
package leetcode.easy; public class ArrangingCoins { public int arrangeCoins(int n) { int i = 0; while (true) { if (i <= n) { n = n - i; i++; } else { return i - 1; } } } @org.junit.Test public void test() { System.out.println(arrangeCoins(5)); System.out.println(arrangeCoins(8)); } }