Introduction

In this blog post, we will explore how to solve the LeetCode problem "944" 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

You are given an array of n strings strs, all of the same length. The strings can be arranged such that there is one on each line, making a grid. For example, strs = ["abc", "bce", "cae"] can be arranged as follows: abc bce cae You want to delete the columns that are not sorted lexicographically. In the above example (0-indexed), columns 0 ('a', 'b', 'c') and 2 ('c', 'e', 'e') are sorted, while column 1 ('b', 'c', 'a') is not, so you would delete column 1. Return the number of columns that you will delete. Example 1: Input: strs = ["cba","daf","ghi"] Output: 1 Explanation: The grid looks as follows: cba daf ghi Columns 0 and 2 are sorted, but column 1 is not, so you only need to delete 1 column. Example 2: Input: strs = ["a","b"] Output: 0 Explanation: The grid looks as follows: a b Column 0 is the only column and is sorted, so you will not delete any columns. Example 3: Input: strs = ["zyx","wvu","tsr"] Output: 3 Explanation: The grid looks as follows: zyx wvu tsr All 3 columns are not sorted, so you will delete all 3. Constraints: n == strs.length 1 <= n <= 100 1 <= strs[i].length <= 1000 strs[i] consists of lowercase English letters.

Explanation

Here's the solution:

• Iterate through each column of the grid.
• For each column, check if it is sorted lexicographically by comparing adjacent characters.

• If a column is not sorted, increment the count of columns to be deleted.

• Runtime Complexity: O(n m), where n is the number of strings and m is the length of each string. *Storage Complexity: O(1).

Code

    def minDeletionSize(strs: list[str]) -> int:
    """
    You are given an array of n strings strs, all of the same length. The strings can be arranged such that there is one on each line, making a grid.
    You want to delete the columns that are not sorted lexicographically.
    Return the number of columns that you will delete.

    Example 1:
    Input: strs = ["cba","daf","ghi"]
    Output: 1
    Explanation: The grid looks as follows:
      cba
      daf
      ghi
    Columns 0 and 2 are sorted, but column 1 is not, so you only need to delete 1 column.

    Example 2:
    Input: strs = ["a","b"]
    Output: 0
    Explanation: The grid looks as follows:
      a
      b
    Column 0 is the only column and is sorted, so you will not delete any columns.

    Example 3:
    Input: strs = ["zyx","wvu","tsr"]
    Output: 3
    Explanation: The grid looks as follows:
      zyx
      wvu
      tsr
    All 3 columns are not sorted, so you will delete all 3.

    Constraints:
    n == strs.length
    1 <= n <= 100
    1 <= strs[i].length <= 1000
    strs[i] consists of lowercase English letters.
    """

    n = len(strs)
    m = len(strs[0])
    deleted_columns = 0

    for j in range(m):
        for i in range(1, n):
            if strs[i][j] < strs[i - 1][j]:
                deleted_columns += 1
                break

    return deleted_columns