Introduction

In this blog post, we will explore how to solve the LeetCode problem "1523" 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 two non-negative integers low and high. Return the count of odd numbers between low and high (inclusive). Example 1: Input: low = 3, high = 7 Output: 3 Explanation: The odd numbers between 3 and 7 are [3,5,7]. Example 2: Input: low = 8, high = 10 Output: 1 Explanation: The odd numbers between 8 and 10 are [9]. Constraints: 0 <= low <= high <= 10^9

Explanation

Here's an efficient solution to count odd numbers within a given range:

• Direct Calculation: Instead of iterating through the range, we can directly calculate the number of odd numbers using integer division and considering whether the boundaries are odd or even.

• Handle Edge Cases: Special attention is paid to the inclusive nature of the range and whether low and high are odd or even to ensure correct calculation.

• Optimization: Avoid loops or recursion. The logic leverages constant-time arithmetic operations.

• Runtime & Storage Complexity: O(1) runtime and O(1) storage.

Code

    def count_odds(low: int, high: int) -> int:
    """
    Counts the number of odd numbers between low and high (inclusive).

    Args:
        low: The lower bound (inclusive).
        high: The upper bound (inclusive).

    Returns:
        The number of odd numbers in the range.
    """
    n = (high - low) // 2
    if low % 2 != 0 or high % 2 != 0:
        n += 1
    return n