LeetCode_441. Arranging Coins

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));
	}
}