Introduction

In this blog post, we will explore how to solve the LeetCode problem "1051" 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

A school is trying to take an annual photo of all the students. The students are asked to stand in a single file line in non-decreasing order by height. Let this ordering be represented by the integer array expected where expected[i] is the expected height of the ith student in line. You are given an integer array heights representing the current order that the students are standing in. Each heights[i] is the height of the ith student in line (0-indexed). Return the number of indices where heights[i] != expected[i]. Example 1: Input: heights = [1,1,4,2,1,3] Output: 3 Explanation: heights: [1,1,4,2,1,3] expected: [1,1,1,2,3,4] Indices 2, 4, and 5 do not match. Example 2: Input: heights = [5,1,2,3,4] Output: 5 Explanation: heights: [5,1,2,3,4] expected: [1,2,3,4,5] All indices do not match. Example 3: Input: heights = [1,2,3,4,5] Output: 0 Explanation: heights: [1,2,3,4,5] expected: [1,2,3,4,5] All indices match. Constraints: 1 <= heights.length <= 100 1 <= heights[i] <= 100

Explanation

Here's an efficient solution to the problem:

• Sorting: Create a sorted copy of the input heights array. This sorted array represents the expected arrangement.
• Comparison: Iterate through both the original heights and the sorted expected arrays, comparing elements at each index.

• Counting Mismatches: Increment a counter each time the elements at the same index in the two arrays are different.

• Runtime Complexity: O(n log n), where n is the number of students (due to sorting). Storage Complexity: O(n), for storing the sorted copy of the array.

Code

    def heightChecker(heights):
    """
    Calculates the number of indices where heights[i] != expected[i].

    Args:
        heights: A list of integers representing the current order of student heights.

    Returns:
        The number of mismatched indices.
    """
    expected = sorted(heights)
    mismatched_count = 0
    for i in range(len(heights)):
        if heights[i] != expected[i]:
            mismatched_count += 1
    return mismatched_count