955. Delete Columns to Make Sorted II

You are given an array of `n` strings `strs`, all of the same length.

We may choose any deletion indices, and we delete all the characters in those indices for each string.

For example, if we have `strs = ["abcdef","uvwxyz"]` and deletion indices `{0, 2, 3}`, then the final array after deletions is `["bef", "vyz"]`.

Suppose we chose a set of deletion indices `answer` such that after deletions, the final array has its elements in lexicographic order (i.e., `strs <= strs <= strs <= ... <= strs[n - 1]`). Return the minimum possible value of `answer.length`.

Example 1:

```Input: strs = ["ca","bb","ac"]
Output: 1
Explanation:
After deleting the first column, strs = ["a", "b", "c"].
Now strs is in lexicographic order (ie. strs <= strs <= strs).
We require at least 1 deletion since initially strs was not in lexicographic order, so the answer is 1.
```

Example 2:

```Input: strs = ["xc","yb","za"]
Output: 0
Explanation:
strs is already in lexicographic order, so we do not need to delete anything.
Note that the rows of strs are not necessarily in lexicographic order:
i.e., it is NOT necessarily true that (strs <= strs <= ...)
```

Example 3:

```Input: strs = ["zyx","wvu","tsr"]
Output: 3
Explanation: We have to delete every column.
```

Constraints:

• `n == strs.length`
• `1 <= n <= 100`
• `1 <= strs[i].length <= 100`
• `strs[i]` consists of lowercase English letters.

955. Delete Columns to Make Sorted II
``````struct Solution;

impl Solution {
fn min_deletion_size(a: Vec<String>) -> i32 {
let n = a.len();
let mut sorted = vec!["".to_string(); n];
let a: Vec<Vec<char>> = a.into_iter().map(|s| s.chars().collect()).collect();
let m = a.len();
for j in 0..m {
for i in 0..n {
sorted[i].push(a[i][j]);
}
if sorted.windows(2).any(|w| w > w) {
for i in 0..n {
sorted[i].pop();
}
}
}
(m - sorted.len()) as i32
}
}

#[test]
fn test() {
let a = vec_string!["ca", "bb", "ac"];
let res = 1;
assert_eq!(Solution::min_deletion_size(a), res);
let a = vec_string!["xc", "yb", "za"];
let res = 0;
assert_eq!(Solution::min_deletion_size(a), res);
let a = vec_string!["zyx", "wvu", "tsr"];
let res = 3;
assert_eq!(Solution::min_deletion_size(a), res);
}
``````