Easy

Quiz

#441 Arranging Coins

APPROACH

You have n coins and are building a staircase where row i requires exactly i coins. Use coins left-to-right, row by row; the last row may remain incomplete. Given n, return the count of fully completed rows.

Example 1:

Input: n = 5

Output: 2

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

Example 2:

Input: n = 8

Output: 3

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

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What is the optimal approach for this problem?