Introduction

In this blog post, we will explore how to solve the LeetCode problem "1556" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

Given an integer n, add a dot (".") as the thousands separator and return it in string format. Example 1: Input: n = 987 Output: "987" Example 2: Input: n = 1234 Output: "1.234" Constraints: 0 <= n <= 231 - 1

Explanation

Here's a breakdown of the approach, followed by the Python code:

• Convert to String and Iterate Backwards: Convert the integer to its string representation. Iterate through the string from right to left (least significant digit to most significant digit).
• Insert Separators: Insert a dot (".") after every three digits.

• Handle Leading Dot: Remove any leading dot that might result from the insertion process.

• Runtime Complexity: O(N), where N is the number of digits in the input integer. Storage Complexity: O(N)

Code

    def thousand_separator(n: int) -> str:
    """
    Given an integer n, add a dot (".") as the thousands separator and return it in string format.

    Example 1:
    Input: n = 987
    Output: "987"

    Example 2:
    Input: n = 1234
    Output: "1.234"

    Constraints:
    0 <= n <= 231 - 1
    """
    s = str(n)
    res = ""
    count = 0
    for i in range(len(s) - 1, -1, -1):
        res = s[i] + res
        count += 1
        if count == 3 and i != 0:
            res = "." + res
            count = 0
    return res