标签：Nging col nbsp int fail issue str follow can
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.
First Attempt:
Time Limit Exceeded.
class Solution { public int arrangeCoins(int n) { int sum = 0; int k = 0; for(int i =1; sum<=n; i++){ if(sum+i<=n){ sum = sum+i; } else{ k = i; break; } } if((n-sum)==k){ return k; } else return k-1; } }
Second Attempt:
Using Formula, performs much better with the test cases, but still some failed.
The Issue lies in that 8* n if the type is int, it would cause overflow.
we could transfer it to long before we multiply.
thus it is a math problem.
All test cases passed.
(Easy) Arranging Coins - LeetCode
标签：Nging col nbsp int fail issue str follow can
原文地址：https://www.cnblogs.com/codingyangmao/p/11431047.html
