package LeetCode_944 /** * 944. Delete Columns to Make Sorted * https://leetcode.com/problems/delete-columns-to-make-sorted/ * 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: 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: 1. n == strs.length 2. 1 <= n <= 100 3. 1 <= strs[i].length <= 1000 strs[i] consists of lowercase English letters. * */ class Solution { /* * solution: brute force, Time:O(n^2), Space:O(1) * */ fun minDeletionSize(strs: Array<String>): Int { var needDeleteCount = 0 val cols = strs[0].length for (i in 0 until cols) { for (j in 1 until strs.size) { if (strs[j][i] < strs[j-1][i]) { needDeleteCount++
break
} } } return needDeleteCount } }