944. Delete Columns to Make Sorted

/*
 * @lc app=leetcode id=944 lang=cpp
 *
 * [944] Delete Columns to Make Sorted
 *
 * https://leetcode.com/problems/delete-columns-to-make-sorted/description/
 *
 * algorithms
 * Easy (74.65%)
 * Likes:    1740
 * Dislikes: 2898
 * Total Accepted:    205.4K
 * Total Submissions: 274.8K
 * Testcase Example:  '["cba","daf","ghi"]'
 *
 * 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.
 *
 *
 */

// @lc code=start
class Solution {
public:
    int minDeletionSize(vector<string>& strs) {
        int m = strs.size(), n = strs[0].size();
        int cnt = 0;
        for (int j = 0; j < n; j++) {
            for (int i = 0; i < m - 1; i++) {
                if (strs[i][j] > strs[i + 1][j]) {
                    cnt++; break;
                }
            }
        }
        return cnt;
    }
};
// @lc code=end