p441

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LeetCode p441 Arranging Coins 题解

1.题目：

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.

题意：

给你n个硬币，按如上规则排列。第1行1个，第2行2个….
问能够排满多少行。

2.解题思路:

见代码，循环减一次。
&&开始想直接数学推。。但是测试的数太大boom了。。

3.代码

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public class Solution {
    public int arrangeCoins(int n) {
        int i=0;
		while (n>=i)
		{
			n-=i;
			i++;
		}
		
		return i-1;
    }
}

4.一些总结：