You are given an array of $n$ strings strs, where all strings have equal length.

You may choose a set of column indices to delete. After deleting the characters at the selected indices from every string, each individual string in strs must be in nondecreasing lexicographical order.

Return the minimum number of column deletions required so that every string in strs satisfies this condition.

Constraints:

• n $==$ strs.length

• $1 \leq$ n $\leq 100$

• $1 \leq$ strs[i].length $\leq 100$

• strs[i] consists of lowercase English letters.

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.