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

You may choose any set of column indices to delete. When a column index is deleted, the character at that index is removed from every string in strs.

Return the minimum number of column deletions required so that the remaining array of strings is in lexicographical order, meaning strs[$0$] \leq strs[$1$] \leq strs[$2$] \leq \dots \leq strs[n - $1$].

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.